Commit f95499c303 ("n_tty: Don't wait for buffer work in read() loop")
introduces a race window where a pty master can be signalled that the pty
slave was closed before all the data that the slave wrote is delivered.
Commit f8747d4a46 ("tty: Fix pty master read() after slave closes") fixed the
problem in case of n_tty_read, but the problem still exists for n_tty_poll.
This can be seen by running 'for ((i=0; i<100;i++));do ./test.py ;done'
where test.py is:
import os, select, pty
(pid, pty_fd) = pty.fork()
if pid == 0:
os.write(1, 'This string should be received by parent')
else:
poller = select.epoll()
poller.register( pty_fd, select.EPOLLIN )
ready = poller.poll( 1 * 1000 )
for fd, events in ready:
if not events & select.EPOLLIN:
print 'missed POLLIN event'
else:
print os.read(fd, 100)
poller.close()
The string from the slave is missed several times.
This patch takes the same approach as the fix for read and special cases
this condition for poll.
Tested on 3.16.
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The info pointer points to an uninitialized kmalloced space.
If a device doesn't have clk property, then info->clk may
have unpredicated value and cause call trace. So use kzalloc
to make sure it is NULL initialized.
Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can call this function for a dummy console that doesn't support
setting the font mapping, which will result in a null ptr BUG. So check
for this case and return error for consoles w/o font mapping support.
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=59321
Signed-off-by: Imre Deak <imre.deak@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The calculation of value quot for highspeed register set to three
was wrong. This patch fixes the calculation so that the serial port
for baudrates bigger then 576000 baud is working correctly.
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Only print one warning when a task is on the read_wait or write_wait
wait queue at final tty release.
Cc: <stable@vger.kernel.org> # 3.4.x+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kernel oops can cause the tty to be unreleaseable (for example, if
n_tty_read() crashes while on the read_wait queue). This will cause
tty_release() to endlessly loop without sleeping.
Use a killable sleep timeout which grows by 2n+1 jiffies over the interval
[0, 120 secs.) and then jumps to forever (but still killable).
NB: killable just allows for the task to be rewoken manually, not
to be terminated.
Cc: <stable@vger.kernel.org> # since before 2.6.32
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_get_baud_rate() will return baud == 0 if the max rate is set
to the "magic" 38400 rate and the SPD_* flags are also specified.
On the first iteration, if the current baud rate is higher than the
max, the baud rate is clamped at the max (which in the degenerate
case is 38400). On the second iteration, the now-"magic" 38400 baud
rate selects the possibly higher alternate baud rate indicated by
the SPD_* flag. Since only two loop iterations are performed, the
loop is exited, a kernel WARNING is generated and a baud rate of
0 is returned.
Reproducible with:
setserial /dev/ttyS0 spd_hi base_baud 38400
Only perform the "magic" 38400 -> SPD_* baud transform on the first
loop iteration, which prevents the degenerate case from recognizing
the clamped baud rate as the "magic" 38400 value.
Reported-by: Robert Święcki <robert@swiecki.net>
Cc: <stable@vger.kernel.org> # all
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull slave-dmaengine updates from Vinod Koul:
"For dmaengine contributions we have:
- designware cleanup by Andy
- my series moving device_control users to dmanegine_xxx APIs for
later removal of device_control API
- minor fixes spread over drivers mainly mv_xor, pl330, mmp, imx-sdma
etc"
* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (60 commits)
serial: atmel: add missing dmaengine header
dmaengine: remove FSLDMA_EXTERNAL_START
dmaengine: freescale: remove FSLDMA_EXTERNAL_START control method
carma-fpga: move to fsl_dma_external_start()
carma-fpga: use dmaengine_xxx() API
dmaengine: freescale: add and export fsl_dma_external_start()
dmaengine: add dmaengine_prep_dma_sg() helper
video: mx3fb: use dmaengine_terminate_all() API
serial: sh-sci: use dmaengine_terminate_all() API
net: ks8842: use dmaengine_terminate_all() API
mtd: sh_flctl: use dmaengine_terminate_all() API
mtd: fsmc_nand: use dmaengine_terminate_all() API
V4L2: mx3_camer: use dmaengine_pause() API
dmaengine: coh901318: use dmaengine_terminate_all() API
pata_arasan_cf: use dmaengine_terminate_all() API
dmaengine: edma: check for echan->edesc => NULL in edma_dma_pause()
dmaengine: dw: export probe()/remove() and Co to users
dmaengine: dw: enable and disable controller when needed
dmaengine: dw: always export dw_dma_{en,dis}able
dmaengine: dw: introduce dw_dma_on() helper
...
The atmel serial driver uses dmaengine APIs but never included the dmaengine
header as it was getting inculded thru one of driver headers.
commit 3d588f83e4 - "dmaengine: dw: split
dma-dw.h to platform and private parts" broke this as it moved headers
around. Fix this by doing the right thing to include the dmaengine header
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 08f738be88 (serial: at91: add tx dma support)
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
The drivers should use dmaengine_terminate_all() API instead of
accessing the device_control which will be deprecated soon
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave
Hansen)
- Various sched/idle refinements for better idle handling (Nicolas
Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot)
- sched/numa updates and optimizations (Rik van Riel)
- sysbench speedup (Vincent Guittot)
- capacity calculation cleanups/refactoring (Vincent Guittot)
- Various cleanups to thread group iteration (Oleg Nesterov)
- Double-rq-lock removal optimization and various refactorings
(Kirill Tkhai)
- various sched/deadline fixes
... and lots of other changes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
sched/dl: Use dl_bw_of() under rcu_read_lock_sched()
sched/fair: Delete resched_cpu() from idle_balance()
sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
sched: Improve sysbench performance by fixing spurious active migration
sched/x86: Fix up typo in topology detection
x86, sched: Add new topology for multi-NUMA-node CPUs
sched/rt: Use resched_curr() in task_tick_rt()
sched: Use rq->rd in sched_setaffinity() under RCU read lock
sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask'
sched: Use dl_bw_of() under RCU read lock
sched/fair: Remove duplicate code from can_migrate_task()
sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW
sched: print_rq(): Don't use tasklist_lock
sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
sched: Fix the task-group check in tg_has_rt_tasks()
sched/fair: Leverage the idle state info when choosing the "idlest" cpu
sched: Let the scheduler see CPU idle states
sched/deadline: Fix inter- exclusive cpusets migrations
sched/deadline: Clear dl_entity params when setscheduling to different class
sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault()
...
Pull powerpc updates from Michael Ellerman:
"Here's a first pull request for powerpc updates for 3.18.
The bulk of the additions are for the "cxl" driver, for IBM's Coherent
Accelerator Processor Interface (CAPI). Most of it's in drivers/misc,
which Greg & Arnd maintain, Greg said he was happy for us to take it
through our tree.
There's the usual minor cleanups and fixes, including a bit of noise
in drivers from some of those. A bunch of updates to our EEH code,
which has been getting more testing. Several nice speedups from
Anton, including 20% in clear_page().
And a bunch of updates for freescale from Scott"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (130 commits)
cxl: Fix afu_read() not doing finish_wait() on signal or non-blocking
cxl: Add documentation for userspace APIs
cxl: Add driver to Kbuild and Makefiles
cxl: Add userspace header file
cxl: Driver code for powernv PCIe based cards for userspace access
cxl: Add base builtin support
powerpc/mm: Add hooks for cxl
powerpc/opal: Add PHB to cxl mode call
powerpc/mm: Add new hash_page_mm()
powerpc/powerpc: Add new PCIe functions for allocating cxl interrupts
cxl: Add new header for call backs and structs
powerpc/powernv: Split out set MSI IRQ chip code
powerpc/mm: Export mmu_kernel_ssize and mmu_linear_psize
powerpc/msi: Improve IRQ bitmap allocator
powerpc/cell: Make spu_flush_all_slbs() generic
powerpc/cell: Move data segment faulting code out of cell platform
powerpc/cell: Move spu_handle_mm_fault() out of cell platform
powerpc/pseries: Use new defines when calling H_SET_MODE
powerpc: Update contact info in Documentation files
powerpc/perf/hv-24x7: Simplify catalog_read()
...
- Add pvscsi frontend and backend drivers.
- Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses.
- Try and keep memory contiguous during PV memory setup (reduces
SWIOTLB usage).
- Allow front/back drivers to use threaded irqs.
- Support large initrds in PV guests.
- Fix PVH guests in preparation for Xen 4.5
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Merge tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen updates from David Vrabel:
"Features and fixes:
- Add pvscsi frontend and backend drivers.
- Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses.
- Try and keep memory contiguous during PV memory setup (reduces
SWIOTLB usage).
- Allow front/back drivers to use threaded irqs.
- Support large initrds in PV guests.
- Fix PVH guests in preparation for Xen 4.5"
* tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (22 commits)
xen: remove DEFINE_XENBUS_DRIVER() macro
xen/xenbus: Remove BUG_ON() when error string trucated
xen/xenbus: Correct the comments for xenbus_grant_ring()
x86/xen: Set EFER.NX and EFER.SCE in PVH guests
xen: eliminate scalability issues from initrd handling
xen: sync some headers with xen tree
xen: make pvscsi frontend dependant on xenbus frontend
arm{,64}/xen: Remove "EXPERIMENTAL" in the description of the Xen options
xen-scsifront: don't deadlock if the ring becomes full
x86: remove the Xen-specific _PAGE_IOMAP PTE flag
x86/xen: do not use _PAGE_IOMAP PTE flag for I/O mappings
x86: skip check for spurious faults for non-present faults
xen/efi: Directly include needed headers
xen-scsiback: clean up a type issue in scsiback_make_tpg()
xen-scsifront: use GFP_ATOMIC under spin_lock
MAINTAINERS: Add xen pvscsi maintainer
xen-scsiback: Add Xen PV SCSI backend driver
xen-scsifront: Add Xen PV SCSI frontend driver
xen: Add Xen pvSCSI protocol description
xen/events: support threaded irqs for interdomain event channels
...
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Merge tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linux
Pull file locking related changes from Jeff Layton:
"This release is a little more busy for file locking changes than the
last:
- a set of patches from Kinglong Mee to fix the lockowner handling in
knfsd
- a pile of cleanups to the internal file lease API. This should get
us a bit closer to allowing for setlease methods that can block.
There are some dependencies between mine and Bruce's trees this cycle,
and I based my tree on top of the requisite patches in Bruce's tree"
* tag 'locks-v3.18-1' of git://git.samba.org/jlayton/linux: (26 commits)
locks: fix fcntl_setlease/getlease return when !CONFIG_FILE_LOCKING
locks: flock_make_lock should return a struct file_lock (or PTR_ERR)
locks: set fl_owner for leases to filp instead of current->files
locks: give lm_break a return value
locks: __break_lease cleanup in preparation of allowing direct removal of leases
locks: remove i_have_this_lease check from __break_lease
locks: move freeing of leases outside of i_lock
locks: move i_lock acquisition into generic_*_lease handlers
locks: define a lm_setup handler for leases
locks: plumb a "priv" pointer into the setlease routines
nfsd: don't keep a pointer to the lease in nfs4_file
locks: clean up vfs_setlease kerneldoc comments
locks: generic_delete_lease doesn't need a file_lock at all
nfsd: fix potential lease memory leak in nfs4_setlease
locks: close potential race in lease_get_mtime
security: make security_file_set_fowner, f_setown and __f_setown void return
locks: consolidate "nolease" routines
locks: remove lock_may_read and lock_may_write
lockd: rip out deferred lock handling from testlock codepath
NFSD: Get reference of lockowner when coping file_lock
...
cycle:
- Increase the default ARCH_NR_GPIO from 256 to 512. This
was done to avoid having a custom <asm/gpio.h> header for
the x86 architecture - GPIO is custom and complicated
enough as it is already! We want to move to a radix to
store the descriptors going forward, and finally get rid
of this fixed array size altogether.
- Endgame patching of the gpio_remove() semantics initiated
by Abdoulaye Berthe. It is not accepted by the system that
the removal of a GPIO chip fails during e.g. reboot or
shutdown, and therefore the return value has now painfully
been refactored away. For special cases like GPIO expanders
on a hot-pluggable bus like USB, we may later add some
gpiochip_try_remove() call, but for the cases we have now,
return values are moot.
- Some incremental refactoring of the gpiolib core and ACPI
GPIO library for more descriptor usage.
- Refactor the chained IRQ handler set-up method to handle
also threaded, nested interrupts and set up the parent IRQ
correctly. Switch STMPE and TC3589x drivers to use this
registration method.
- Add a .irq_not_threaded flag to the struct gpio_chip, so
that also GPIO expanders that block but are still not
using threaded IRQ handlers.
- New drivers for the ARM64 X-Gene SoC GPIO controller.
- The syscon GPIO driver has been improved to handle the
"DSP GPIO" found on the TI Keystone 2 SoC:s.
- ADNP driver switched to use gpiolib irqchip helpers.
- Refactor the DWAPB driver to support being instantiated
from and MFD cell (platform device).
- Incremental feature improvement in the Zynq, MCP23S08,
DWAPB, OMAP, Xilinx and Crystalcove drivers.
- Various minor fixes.
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Merge tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO changes from Linus Walleij:
"This is the bulk of GPIO changes for the v3.18 development cycle:
- Increase the default ARCH_NR_GPIO from 256 to 512. This was done
to avoid having a custom <asm/gpio.h> header for the x86
architecture - GPIO is custom and complicated enough as it is
already! We want to move to a radix to store the descriptors going
forward, and finally get rid of this fixed array size altogether.
- Endgame patching of the gpio_remove() semantics initiated by
Abdoulaye Berthe. It is not accepted by the system that the
removal of a GPIO chip fails during eg reboot or shutdown, and
therefore the return value has now painfully been refactored away.
For special cases like GPIO expanders on a hot-pluggable bus like
USB, we may later add some gpiochip_try_remove() call, but for the
cases we have now, return values are moot.
- Some incremental refactoring of the gpiolib core and ACPI GPIO
library for more descriptor usage.
- Refactor the chained IRQ handler set-up method to handle also
threaded, nested interrupts and set up the parent IRQ correctly.
Switch STMPE and TC3589x drivers to use this registration method.
- Add a .irq_not_threaded flag to the struct gpio_chip, so that also
GPIO expanders that block but are still not using threaded IRQ
handlers.
- New drivers for the ARM64 X-Gene SoC GPIO controller.
- The syscon GPIO driver has been improved to handle the "DSP GPIO"
found on the TI Keystone 2 SoC:s.
- ADNP driver switched to use gpiolib irqchip helpers.
- Refactor the DWAPB driver to support being instantiated from and
MFD cell (platform device).
- Incremental feature improvement in the Zynq, MCP23S08, DWAPB, OMAP,
Xilinx and Crystalcove drivers.
- Various minor fixes"
* tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (52 commits)
gpio: pch: Build context save/restore only for PM
pinctrl: abx500: get rid of unused variable
gpio: ks8695: fix 'else should follow close brace '}''
gpio: stmpe: add verbose debug code
gpio: stmpe: fix up interrupt enable logic
gpio: staticize xway_stp_init()
gpio: handle also nested irqchips in the chained handler set-up
gpio: set parent irq on chained handlers
gpiolib: irqchip: use irq_find_mapping while removing irqchip
gpio: crystalcove: support virtual GPIO
pinctrl: bcm281xx: make Kconfig dependency more strict
gpio: kona: enable only on BCM_MOBILE or for compile testing
gpio, bcm-kona, LLVMLinux: Remove use of __initconst
gpio: Fix ngpio in gpio-xilinx driver
gpio: dwapb: fix pointer to integer cast
gpio: xgene: Remove unneeded #ifdef CONFIG_OF guard
gpio: xgene: Remove unneeded forward declation for struct xgene_gpio
gpio: xgene: Fix missing spin_lock_init()
gpio: ks8695: fix switch case indentation
gpiolib: add irq_not_threaded flag to gpio_chip
...
Here's the big tty/serial driver patchset for 3.18-rc1.
Lots of little things in here, some good work from Peter Hurley on the
tty core, and in lots of drivers. There are also lots of other driver
updates in here as well, full details in the changelog below.
All have been in the linux-next tree for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here's the big tty/serial driver patchset for 3.18-rc1.
Lots of little things in here, some good work from Peter Hurley on the
tty core, and in lots of drivers. There are also lots of other driver
updates in here as well, full details in the changelogs.
All have been in the linux-next tree for a while"
* tag 'tty-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (99 commits)
Revert "serial/core: Initialize the console pm state"
tty: serial: 8250: use 32bit variable for rpm_tx_active
tty: serial: msm: Add earlycon support
serial/core: Initialize the console pm state
serial: asc: Conditionally use readl_relaxed (COMPILE_TEST)
serial: of-serial: add PM suspend/resume support
m68k: AMIGA_BUILTIN_SERIAL should depend on TTY
asm/uapi: Add definition of TIOC[SG]RS485
tty/metag_da: Add console_poll module parameter
serial: 8250_pci: remove rts_n override from Baytrail quirk
serial: cadence: Add generic earlycon support
serial: imx: change the wait even to interruptiable
serial: imx: terminate the RX DMA when the UART is suspending
serial: imx: fix throttle/unthrottle callbacks for hardware assisted flow control
serial: 8250: Add Quark X1000 to 8250_pci.c
tty: omap-serial: pull out calculation from baud_is_mode16
tty: omap-serial: fix division by zero
xen_hvc: no reason to write the type key on xenstore
tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
...
Cheers,
Rusty.
PS. My virtio-next tree is empty: DaveM took the patches I had. There might
be a virtio-rng starvation fix, but so far it's a bit voodoo so I will
get to that in the next two days or it will wait.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module update from Rusty Russell:
"Nothing major: support for compressing modules, and auto-tainting
params.
PS. My virtio-next tree is empty: DaveM took the patches I had. There
might be a virtio-rng starvation fix, but so far it's a bit voodoo
so I will get to that in the next two days or it will wait"
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
moduleparam: Resolve missing-field-initializer warning
kbuild: handle module compression while running 'make modules_install'.
modinst: wrap long lines in order to enhance cmd_modules_install
modsign: lookup lines ending in .ko in .mod files
modpost: simplify file name generation of *.mod.c files
modpost: reduce visibility of symbols and constify r/o arrays
param: check for tainting before calling set op.
drm/i915: taint the kernel if unsafe module parameters are set
module: add module_param_unsafe and module_param_named_unsafe
module: make it possible to have unsafe, tainting module params
module: rename KERNEL_PARAM_FL_NOARG to avoid confusion
The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse
errors.
Replace the uses with standard structure definitions instead. This is
similar to pci and usb device registration.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This reverts commit a86713b153.
Kevin Hilman writes:
Multiple boot failures on ARM[1] were bisected down to this
patch.
How was this patch tested, and on which platforms?
Also, the changelog states that this should be done only for
UART_CAP_SLEEP, but the patch does it for every UART.
Greg, I suggest this patch be dropped from tty-next until it has
been better described and tested.
[1] http://lists.linaro.org/pipermail/kernel-build-reports/2014-October/005550.html
Reported-by: Kevin Hilman <khilman@kernel.org>
Cc: Sudhir Sreedharan <ssreedharan@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no need for yet another copy of the command line, just
use boot_command_line like everyone else.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add support for DT based and command line based early console on platforms
with the msm serial hardware.
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For console devices having UART_CAP_SLEEP capability, the uart_pm_state has
to be initialized to UART_PM_STATE_ON. Otherwise the LCR regiser values
are reinitialized when uart_change_pm is called from uart_configure_port.
Signed-off-by: Sudhir Sreedharan <ssreedharan@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 08177ece59 ("serial: asc: Adopt readl_/writel_relaxed()) is
regressing the m68k allmodconfig build. This is due to the unconditional
use of readl_relaxed() which, although documented, does not currently
exist for m68k.
This is trivially fixable for st-asc because we can just update the
asc_in() accessor to make this conditional.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds PM suspend/resume support for the of-serial driver
to provide power management support on devices attatched to it.
Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the metag_da console channel is write only, it doesn't get
polled for incoming data. This is for performance & latency reasons as
polling blocks the processor for a significant amount of time waiting
for the JTAG probe to respond to the request and restart the thread.
This means that the console channel cannot be used for a login prompt,
so ttyDA2 is usually used instead.
In a virtual environment with a virtual DA such as QEMU however the
polling is much cheaper as the request can be handled immediately. It is
useful to be able to enable polling in such an environment in order to
get both the kernel log and a usable login prompt on the same DA
channel.
Add a console_poll module parameter which allows polling to be enabled
for the console channel. It defaults to off as that is the current
behaviour for good reason on real hardware.
It can be enabled by appending metag_da.console_poll to the kernel
command line.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It should not be used together with Auto Flow Control, and
Auto Flow Control is always enabled on Baytrail.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add earlycon support for the cadence serial port.
This is based on recent patches:
"tty/serial: pl011: add generic earlycon support"
(sha1: 0d3c673e78)
"tty/serial: add arm/arm64 semihosting earlycon"
(sha1: d50d7269eb)
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The wait_event() makes the application hang for ever in the following case:
[1] the hardware flow control is enabled.
[2] the other end (or the remote end) is terminated, and the TX is still
waiting for the hardware flow control signal to become asserted.
This patch fixes it by changing the wait_event to wait_event_interruptible.
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the uart port is suspending, the RX data is useless.
So in this case, we can terminate the RX DMA right now.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
when the 'CTSC' bit is negated. 'CTS' has no function when 'CTSC' is asserted.
0: The CTS pin is high (inactive)
1: The CTS pin is low (active)
For throttle, it needs to clear 'CTS' and 'CTSC' bits.
For unthrottle, it needs to enable 'CTS' and 'CTSC' bits.
The patch just fix the issue.
Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Quark X1000 contains two designware derived 8250 serial ports.
Each port has a unique PCI configuration space consisting of
BAR0:UART BAR1:DMA respectively.
Unlike the standard 8250 the register width is 32 bits for RHR,IER etc
The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a
bitrate of up to about 2.76 megabits per second.
This patch enables standard 8250 mode
Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To determine the correct divisor, we need to know the difference between
the desired baud rate and the actual baud rate. The calculation for this
difference is implemented twice within omap_serial_baud_is_mode16().
Pull out the calculation for easier maintenance.
While at it, remove the CamelCasing from the variable names.
Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
calculated n values in serial_omap_is_baud_mode16() may become 0. This
causes a division by zero when calculating the difference between
calculated and desired baud rates. To prevent this, cap the n13 and n16
values on 1.
Division by zero in kernel.
[<c00132e0>] (unwind_backtrace) from [<c00112ec>] (show_stack+0x10/0x14)
[<c00112ec>] (show_stack) from [<c01ed7bc>] (Ldiv0+0x8/0x10)
[<c01ed7bc>] (Ldiv0) from [<c023805c>] (serial_omap_baud_is_mode16+0x4c/0x68)
[<c023805c>] (serial_omap_baud_is_mode16) from [<c02396b4>] (serial_omap_set_termios+0x90/0x8d8)
[<c02396b4>] (serial_omap_set_termios) from [<c0230a0c>] (uart_change_speed+0xa4/0xa8)
[<c0230a0c>] (uart_change_speed) from [<c0231798>] (uart_set_termios+0xa0/0x1fc)
[<c0231798>] (uart_set_termios) from [<c022bb44>] (tty_set_termios+0x248/0x2c0)
[<c022bb44>] (tty_set_termios) from [<c022c17c>] (set_termios+0x248/0x29c)
[<c022c17c>] (set_termios) from [<c022c3e4>] (tty_mode_ioctl+0x1c8/0x4e8)
[<c022c3e4>] (tty_mode_ioctl) from [<c0227e70>] (tty_ioctl+0xa94/0xb18)
[<c0227e70>] (tty_ioctl) from [<c00cf45c>] (do_vfs_ioctl+0x4a0/0x560)
[<c00cf45c>] (do_vfs_ioctl) from [<c00cf568>] (SyS_ioctl+0x4c/0x74)
[<c00cf568>] (SyS_ioctl) from [<c000e480>] (ret_fast_syscall+0x0/0x30)
Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The backend type is chosen by the toolstack. Regardless, the frontend
should not care, especially given that it cannot have an effect as the
backend is started before this code is run.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_do_startup() adds UART_IER_RDI and UART_IER_RLSI to ier.
serial8250_stop_rx() should remove both.
This is what the serial-omap driver has been doing and is now moved to
the 8250-core since it does no look to be *that* omap specific.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tony noticed that the old omap-serial driver picked the uart "number"
based on the hint given from device tree or platform device's id.
The 8250 based omap driver doesn't do this because the core code does
not honour the ->line argument which is passed by the driver.
This patch aims to keep the same behaviour as with omap-serial. The
function will first try to use the line suggested ->line argument and
then fallback to the old strategy in case the port is taken.
That means the the third uart will always be ttyS2 even if the previous
two have not been enabled in DT.
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serial8250_do_startup() function unconditionally clears the
interrupts and for that it reads from the RX-FIFO without checking if
there is a byte in the FIFO or not. This works fine on OMAP4+ HW like
AM335x or DRA7.
OMAP3630 ES1.1 (which means probably all OMAP3 and earlier) does not like
this:
|Unhandled fault: external abort on non-linefetch (0x1028) at 0xfb020000
|Internal error: : 1028 [#1] ARM
|Modules linked in:
|CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-00022-g7edcb57-dirty #1213
|task: de0572c0 ti: de058000 task.ti: de058000
|PC is at mem32_serial_in+0xc/0x1c
|LR is at serial8250_do_startup+0x220/0x85c
|Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
|Control: 10c5387d Table: 80004019 DAC: 00000015
|[<c03051d4>] (mem32_serial_in) from [<c0307fe8>] (serial8250_do_startup+0x220/0x85c)
|[<c0307fe8>] (serial8250_do_startup) from [<c0309e00>] (omap_8250_startup+0x5c/0xe0)
|[<c0309e00>] (omap_8250_startup) from [<c030863c>] (serial8250_startup+0x18/0x2c)
|[<c030863c>] (serial8250_startup) from [<c030394c>] (uart_startup+0x78/0x1d8)
|[<c030394c>] (uart_startup) from [<c0304678>] (uart_open+0xe8/0x114)
|[<c0304678>] (uart_open) from [<c02e9e10>] (tty_open+0x1a8/0x5a4)
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While comparing the OMAP-serial and the 8250 part of this I noticed that
the latter does not use run time-pm. Here are the pieces. It is
basically a get before first register access and a last_busy + put after
last access. This has to be enabled from userland _and_ UART_CAP_RPM is
required for this.
The runtime PM can usually work transparently in the background however
there is one exception to this: After serial8250_tx_chars() completes
there still may be unsent bytes in the FIFO (depending on CPU speed vs
baud rate + flow control). Even if the TTY-buffer is empty we do not
want RPM to disable the device because it won't send the remaining
bytes. Instead we leave serial8250_tx_chars() with RPM enabled and wait
for the FIFO empty interrupt. Once we enter serial8250_tx_chars() with
an empty buffer we know that the FIFO is empty and since we are not going
to send anything, we can disable the device.
That xchg() is to ensure that serial8250_tx_chars() can be called
multiple times and only the first invocation will actually invoke the
runtime PM function. So that the last invocation of __stop_tx() will
disable runtime pm.
NOTE: do not enable RPM on the device unless you know what you do! If
the device goes idle, it won't be woken up by incomming RX data _unless_
there is a wakeup irq configured which is usually the RX pin configure
for wakeup via the reset module. The RX activity will then wake up the
device from idle. However the first character is garbage and lost. The
following bytes will be received once the device is up in time. On the
beagle board xm (omap3) it takes approx 13ms from the first wakeup byte
until the first byte that is received properly if the device was in
core-off.
v5…v8:
- drop RPM from serial8250_set_mctrl() it will be used in
restore path which already has RPM active and holds
dev->power.lock
v4…v5:
- add a wrapper around rpm function and introduce UART_CAP_RPM
to ensure RPM put is invoked after the TX FIFO is empty.
v3…v4:
- added runtime to the console code
- removed device_may_wakeup() from serial8250_set_sleep()
Cc: mika.westerberg@linux.intel.com
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The OMAP UART provides support for HW assisted flow control. What is
missing is the support to throttle / unthrottle callbacks which are used
by the omap-serial driver at the moment.
This patch adds the callbacks. It should be safe to add them since they
are only invoked from the serial_core (uart_throttle()) if the feature
flags are set.
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While transmitting a START/STOP char for tcflow(TCION/TCIOFF), prevent
a termios change. Otherwise, a garbage in-band flow control char
may be sent, if the termios change overlaps the transmission setup.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Relocate the file-scope function, send_prio_char(), as a global
helper tty_send_xchar(). Remove the global declarations for
tty_write_lock()/tty_write_unlock(), as these are file-scope only now.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use newly-introduced tty->flow_lock to serialize updates to
tty->flow_stopped (via tcflow()) and with concurrent tty flow
control changes from other sources.
Merge the storage for ->stopped and ->flow_stopped, now that both
flags are serialized by ->flow_lock.
The padding bits are necessary to force the compiler to allocate the
type specified; otherwise, gcc will ignore the type specifier and
allocate the minimum number of bytes necessary to store the bitfield.
In turn, this would allow Alpha EV4 and EV5 cpus to corrupt adjacent
byte storage because those cpus use RMW to store byte and short data.
gcc versions < 4.7.2 will also corrupt storage adjacent to bitfields
smaller than unsigned long on ia64, ppc64, hppa64 and sparc64, thus
requiring more than unsigned int storage (which would otherwise be
sufficient to workaround the Alpha non-atomic byte/short storage problem).
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a master pty is set to packet mode, flow control changes to
the slave pty cause notifications to the master pty via reads and
polls. However, these tests are occurring for all ttys, not
just ptys.
Implement flow control packet mode notifications in the pty driver.
Only the slave side implements the flow control handlers since
packet mode is asymmetric; the master pty receives notifications
for slave-side changes, but not vice versa.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without serialization, the flow control state can become inverted
wrt. the actual hardware state. For example,
CPU 0 | CPU 1
stop_tty() |
lock ctrl_lock |
tty->stopped = 1 |
unlock ctrl_lock |
| start_tty()
| lock ctrl_lock
| tty->stopped = 0
| unlock ctrl_lock
| driver->start()
driver->stop() |
In this case, the flow control state now indicates the tty has
been started, but the actual hardware state has actually been stopped.
Introduce tty->flow_lock spinlock to serialize tty flow control changes.
Split out unlocked __start_tty()/__stop_tty() flavors for use by
ioctl(TCXONC) in follow-on patch.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_set_termios() is called with interrupts enabled; no need to
save and restore the interrupt state when taking the uart port lock.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 64851636d5,
serial: bfin-uart: Remove ASYNC_CTS_FLOW flag for hardware automatic CTS,
open-codes uart_handle_cts_change() when CONFIG_SERIAL_BFIN_HARD_CTSRTS
to skip start and stop tx.
But the CTS interrupt handler _still_ calls uart_handle_cts_change();
only call uart_handle_cts_change() if !CONFIG_SERIAL_BFIN_HARD_CTSRTS.
cc: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty->hw_stopped is not used by the tty core and is thread-unsafe;
hw_stopped is a member of a bitfield whose fields are updated
non-atomically and no lock is suitable for serializing updates.
Replace serial core usage of tty->hw_stopped with uport->hw_stopped.
Use int storage which works around Alpha EV4/5 non-atomic byte storage,
since uart_port uses different locks to protect certain fields within the
structure.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serial core uses the tty port flags, ASYNC_CTS_FLOW and
ASYNC_CD_CHECK, to track whether CTS and DCD changes should be
ignored or handled. However, the tty port flags are not safe for
atomic bit operations and no lock provides serialized updates.
Introduce the struct uart_port status field to track CTS and DCD
enable states, and serialize access with uart port lock. Substitute
uart_cts_enabled() helper for tty_port_cts_enabled().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The serial core provides two helper functions, uart_handle_dcd_change()
and uart_handle_cts_change(), for UART drivers to use at interrupt
time. The serial core expects the UART driver to hold the uart port lock
when calling these helpers to prevent state corruption.
If lockdep enabled, trigger a warning if the uart port lock is not held
when calling these helper functions.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
