This fixes a regression on high clock speeds with the MMCI on
ux500. We need to make sure we derive the passthru clock on the
falling edge of the incoming clock if it shall work at high
frequencies, and on the ux500's there is a special bit for this.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The mmci.h header contained a few registers not clearly marked
as ST Micro only, rectify this and remove the HWFC magic in the
process. The idea is to make the mmci.h header file more ordered
so other vendors with PL180 derivates can see where to put in
their custom register defines.
Includes portions of an earlier patch from Sebastian Rasmussen.
Acked-by: Sebastian Rasmussen <sebastian.rasmussen@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
New IO FPGA implementation for Versatile Express boards contain
MMCI (PL180) cell with FIFO extended to 128 words (512 bytes).
Matt Waddel reports that this patch improves MMC performance on
his vexpress system, and also fixes "mmcblk0: error -5 transferring
data" errors.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Tested-by: Matt Waddel <matt.waddel@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Make Primecell driver probe functions take a const pointer to their
ID tables. Drivers should never modify their ID tables in their
probe handler.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Based on a patch from Linus Walleij.
Add dmaengine based support for DMA to the MMCI driver, using the
Primecell DMA engine interface. The changes over Linus' driver are:
- rename txsize_threshold to dmasize_threshold, as this reflects the
purpose more.
- use 'mmci_dma_' as the function prefix rather than 'dma_mmci_'.
- clean up requesting of dma channels.
- don't release a single channel twice when it's shared between tx and rx.
- get rid of 'dma_enable' bool - instead check whether the channel is NULL.
- detect incomplete DMA at the end of a transfer. Some DMA controllers
(eg, PL08x) are unable to be configured for scatter DMA and also listen
to all four DMA request signals [BREQ,SREQ,LBREQ,LSREQ] from the MMCI.
They can do one or other but not both. As MMCI uses LBREQ/LSREQ for the
final burst/words, PL08x does not transfer the last few words.
- map and unmap DMA buffers using the DMA engine struct device, not the
MMCI struct device - the DMA engine is doing the DMA transfer, not us.
- avoid double-unmapping of the DMA buffers on MMCI data errors.
- don't check for negative values from the dmaengine tx submission
function - Dan says this must never fail.
- use new dmaengine helper functions rather than using the ugly function
pointers directly.
- allow DMA code to be fully optimized away using dma_inprogress() which
is defined to constant 0 if DMA engine support is disabled.
- request maximum segment size from the DMA engine struct device and
set this appropriately.
- removed checking of buffer alignment - the DMA engine should deal with
its own restrictions on buffer alignment, not the individual DMA engine
users.
- removed setting DMAREQCTL - this confuses some DMA controllers as it
causes LBREQ to be asserted for the last seven transfers, rather than
six SREQ and one LSREQ.
- removed burst setting - the DMA controller should not burst past the
transfer size required to complete the DMA operation.
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We don't need to store the number of bytes transferred in our host
structure - we can store this directly in data->bytes_xfered.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We don't need to switch to data available interrupts if there's at
least half a FIFO depth worth of data remaining, as we'll still get
the FIFO half full interrupt. Keep this interrupt masked off until
we have less than half the FIFO depth worth of data remaining.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The sg_miter API provides the required cache maintainence, so we don't
need to do that ourselves. Remove the unnecessary additional cache
maintainence.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The data counter counts the number of bytes transferred on the MMC bus.
When a FIFO overrun occurs, we will not have transferred a FIFOs-worth
of data to memory, and so the data counter will be a FIFOs-worth ahead.
If this occurs on a block boundary, we will report one too many sectors
as successful. Fix this.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We should not report incomplete blocks on error. Return the number of
bytes successfully transferred, rounded down to the nearest block.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When we encounter an error, make sure we complete the transaction
otherwise we'll leave the request dangling.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The MMCIDATACNT register contain the number of byte left at error
not the number of words, so loose the << 2 thing. Further if CRC
fails on the first block, we may end up with a negative number
of transferred bytes which is not good, and the formula was in
wrong order.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Don't read the command response from the registers when either the
command timed out (because there was no response from the card) or
the checksum on the response was invalid.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Chris Ball <cjb@laptop.org>
Implement a suggestion from Russell to drop the use of blockend
interrupts altogether and instead rely on the data counter.
Tested with error-free cards on U300, U8500 and RealView PB1176.
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Make the MMCI announcement printk say which primecell part number
has been found. Display the revision as an unsigned decimal, and
display only the first 8 hex digits of the base address unless it's
larger.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
I misread the datasheet as if bypass mode was not available at all
on the ux500's, I was wrong. It is there, the datasheet just
states that you should not have to use it.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The Ux500 variant of this block has a different divider.
The value used right now is too big and which means a loss
in performance. This fix corrects it. Also expand the math
comments a bit so it's clear what's happening. Further
the Ux500 variant does not like if we use the BYPASS bit,
instead we are supposed to set the clock divider to zero.
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This adds some minor variant data and trickery to enable SDIO
on the ST Micro variants of MMCI/PL180.
Signed-off-by: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On the U300 the MCI_DATAEND and MCI_DATABLOCKEND IRQs can arrive
out-of-order. Replace an ugly #ifdef hack with a proper runtime
solution which models what is really happening.
In the U300 DMA mode and on all Ux500 models, the MCI_DATABLOCKEND
flag isn't properly cleared in hardware following and ACK leading
to all kind of weird behaviour when the flag is still up in
subsequent interrupts, so we add two flags indicating the
error and handle this runtime.
Cc: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The DBx500 variants have only one IRQ line hooked up. Allow these (and
any other implementations which choose to use only one irq) to work by
directing the PIO interrupts also to the first IRQ line.
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
After discovering a problem in regulator reference counting I took Mark
Brown's advice to move the reference count into the MMC core by making the
regulator status a member of struct mmc_host.
I took this opportunity to also implement NULL versions of
the regulator functions so as to rid the driver code from
some ugly #ifdef CONFIG_REGULATOR clauses.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Sundar Iyer <sundar.iyer@stericsson.com>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Cliff Brake <cbrake@bec-systems.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
We have deprecated the distinction between hardware and physical
segments in the block layer. Consolidate the two limits into one in
drivers/mmc/.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Currently the kernel is screaming about slowpath at me for the
wp/cd callbacks. Switch to the _cansleep variants so as to silence
this.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The card may be always present on the board, and for these cases neither
a status callback nor a card detect GPIO is required, and card detection
polling can be disabled.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If an IRQ can be requested on the card detected GPIO, use it instead of
polling.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The Ux500 variant has a 32-word FIFO (TXFIFOEMPTY is asserted when it
has 2 left) and TXFIFOHALFEMPTY is repurposed as TXFIFOBURSTWRITEABLE,
with a burst being defined as 8-words. Likewise for RX.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On some platforms, the GPIO value from the gpio_cd pin doesn't need to
be inverted to get it active high. Add a cd_invert platform data
parameter and change existing platforms using GPIO for CD (only
Realview) to enable it.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (291 commits)
ARM: AMBA: Add pclk support to AMBA bus infrastructure
ARM: 6278/2: fix regression in RealView after the introduction of pclk
ARM: 6277/1: mach-shmobile: Allow users to select HZ, default to 128
ARM: 6276/1: mach-shmobile: remove duplicate NR_IRQS_LEGACY
ARM: 6246/1: mmci: support larger MMCIDATALENGTH register
ARM: 6245/1: mmci: enable hardware flow control on Ux500 variants
ARM: 6244/1: mmci: add variant data and default MCICLOCK support
ARM: 6243/1: mmci: pass power_mode to the translate_vdd callback
ARM: 6274/1: add global control registers definition header file for nuc900
mx2_camera: fix type of dma buffer virtual address pointer
mx2_camera: Add soc_camera support for i.MX25/i.MX27
arm/imx/gpio: add spinlock protection
ARM: Add support for the LPC32XX arch
ARM: LPC32XX: Arch config menu supoport and makefiles
ARM: LPC32XX: Phytec 3250 platform support
ARM: LPC32XX: Misc support functions
ARM: LPC32XX: Serial support code
ARM: LPC32XX: System suspend support
ARM: LPC32XX: GPIO, timer, and IRQ drivers
ARM: LPC32XX: Clock driver
...
The MMC card detection sense has become really confused with negations
at various levels, leading to some platforms not detecting inserted
cards. Fix this by converting everything to positive logic throughout,
thereby getting rid of these negations.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The Ux500 variant has a 24-bit MMCIDATALENGTH register, as opposed to
the 16-bit one on the ARM version.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Although both the U300 and Ux500 use ST variants, the HWFCEN bits are at
different positions, so use the variant_data to store the information.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add a variant_data structure to handle the differences between the
various variants of this peripheral. Add a first quirk for a default
MCICLOCK value, required on the Ux500 variant where the enable bit needs
to be always set, since it controls access to some registers.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Platforms may have some external power control which need to be
controlled from board specific code. Rename the translate_vdd()
callback to vdd_handler() and pass it the power mode.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use the MMC core's ability to poll for card detection. This also has
the advantage of doing the gpio_get_value from a workqueue instead of
timer, allowing the gpio to be on a sleeping gpiochip.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix the data transfer size to allow multi block transfers to work.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The mmci driver's SG list iteration logic assumes that each SG entry
spans only one page, and only maps and flushes one page of the sg. This
is not a valid assumption. Fix it by converting the driver to the
sg_miter API, which correctly handles sgs which span multiple pages.
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Even though many mmc host drivers pass a pm_message_t argument to
mmc_suspend_host() that argument isn't used the by MMC core. As host
drivers are converted to dev_pm_ops they'll have to construct
pm_message_t's (as they won't be passed by the PM subsystem any more) just
to appease the mmc suspend interface.
We might as well just delete the unused paramter.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>ZZ
Acked-by: Sascha Sommer <saschasommer@freenet.de>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This introduce the field f_max into the mmci_platform_data,
making it possible to pass in a desired block clocking frequency
from a board configuration. This is often more desirable than
using a module parameter. We keep the module parameter as a
fallback as well as the default frequency specified for this
parameter if a parameter is not provided.
This also adds some kerneldoc style documentation to the
platform data struct in mmci.h.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This adds support for an 8bit wide bus to the card (data lines
MCIDAT0 through 7 exist) on the ST Micro version and alters the
U300 platform to support this. Also add some ST_ prefix to the
ST-specific registers.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This removes the custom DBG macro in favor of the in-kernel
dev_dbg() macro. Probably a leftover from a time when dev_dbg()
didn't yet exist. Also remove a printk() in favor of dev_err().
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In the U300 some hardware bug makes the status flag not come up
signalling a successful write (or anything else, like an error, for
that matter) on write requests. This little quirk makes the writes
work on U300.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This fixes a leftover instance of using the 0x80 numeral instead
of the new AMBA_VENDOR_ST enum in the MMCI/PL180 driver.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The #ifdefs in the MMCI driver were erroneous and just masking
a bug in the U300 generic GPIO implementation. This removes the
ifdefs and fixes the U300 generic GPIO instead.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This enables the use of a regulator to power the MMCI/PL180
PrimeCell. The OCR mask is calculated and voltage is set using
the new MMC core functions for discovering voltage ranges
in regulators. The platform translate_vdd function which basically
controls the 4 lines out of the PL180 is disabled if you use a
regulator instead.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This moves the mmci platform data definition struct away from
arch/arm/include/asm/mach/mmc.h into the more proper place among
the other primecells in include/linux/amba/mmci.h and at the same
time renames it to "mmci.h", and also the struct in this file
confusingly named mmc_platform_data has been renamed
mmci_platform_data for clarity.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This makes it possible to pass down the host controller
capabilities for the MMCI driver using the platform data. It
also provides the capabilties for the U300 implementation as an
example, and makes sure the 4bit wide mode is set if this is
requested by the ios() now that we can actually set that
capability for a platform.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This breaks out the clock divider set-up code from the
mmci_set_ios() code and surrounds the two register
writes with a host lock so we don't get collisions if
(in future code) two code paths want to change the
clock divider at the same time as can be the case if
we get something like pre/post- clock frequency change
notifications soonish.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This moves the primecell vendor enum definition inside vic.c
out to linux/amba/bus.h where it belongs and replace any
occurances of specific vendor ID:s with the respective enums
instead.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The recent addition of optional gpiolib support to check if a
card was inserted or write protected was really not optional.
It needs this ifdef to become optional so that U300 compiles,
for example.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use gpiolib where available (and when valid GPIOs are provided) for
write protect/card detect status reporting. We fall back to the old
'status' method where gpiolib support is not available.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than open coding the accessors for decoding peripheral IDs,
use the macros already provided.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
I found the PrimeCell/AMBA Bus drivers distrusting the resource
passed in as part of the struct amba_device abstraction. This
patch removes all hard coded resource sizes found in the PrimeCell
drivers and move the responsibility of this definition back to
the platform/board device definition, which already exist and
appear to be correct for all in-tree users of these drivers.
We do this using the resource_size() inline function which was
also replicated in the only driver using the resource size, so
that has been changed too. The KMI_SIZE was left in kmi.h in case
someone likes it. Test-compiled against Versatile and Integrator
defconfigs, seems to work but I don't posess these boards and
cannot test them.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The second argument of the probe method points to the amba_id
structure, so it's better passed with the correct type. None of the
current in-tree drivers uses the pointer, so they have only been
checked for a clean compile.
Change suggested by Russell King.
Signed-off-by: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If MMC debugging is enabled, the mmci driver oopses because the DBG
macro uses host->mmc before it is set. Set it earlier.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Pierre Ossman <pierre@ossman.eu>
This adds __devinit and __devexit macros to the module probe and
remove functions in MMCI. Now includes the __devexit_p() thing too.
Signed-off-by: Linus Walleij <linus.walleij@ericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds support for the ST Microelectronics version of
the PL180 PrimeCell. They use designer ID 0x80 and have a few
alterations/bugfixes related to open drain and HW flow control.
They also add some SDIO registers, I am unsure if these are
in ST HW only or if this is things also added in later ARM
revisions, but they are included in the mmci.h file for
completeness.
Signed-off-by: Linus Walleij <linus.walleij@ericsson.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Where devices only have one consumer, passing a consumer clock ID
has no real benefit, and it only encourages wrong implementations of
the clk API. Remove it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix fastpath issues
Since mmci_request() can be called from a non-interrupt
context, and does, during kernel init, causing a host
of debug messages during boot if you enable spinlock debugging,
we need to use the spinlock calls that save IRQ flags and
restore them.
Signed-off-by: Linus Walleij <triad@df.lth.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Relax requirements on host controllers and only require that they do not
report a transfer count than is larger than the actual one (i.e. a lower
value is okay). This is how many other parts of the kernel behaves so
upper layers should already be prepared to handle that scenario. This
gives us a performance boost on MMC cards.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This fixes some two minor clk issues.
The first is a comparison where a byte will probably wrap around to 0 instead of being saturated to 255, shouldn't be triggered very often but need fixing.
The second is an attempt by the driver to adjust MCLK down to the maximum frequency according to the spec, so we don't accidentally overclock the PL18x block. None of the mach-{versatile|integrator|lh7a40x} that use it in-tree seem to have a problem with this (all are well below 100MHz, typically 33MHz), but some day there will be a problem.
This is not applied on top of the earlier mmci patch for race condition but rather a clean 2.6.25, but I guess it applies without major protests anyway.
Signed-off-by: Linus Walleij <triad@df.lth.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Updated version of 4446/1. This also drops the suggested comparison
of host_remain for == 0, since that doesn't make sense (still works
for us, too). We have verified that this patch solve race problems
on atleast 2 archs at high frequencies.
(Verbatim copy of old patch text below.)
The patch below fixes a race condition in the ARM MMCI PL18x driver.
If new data arrives in the FIFO while existing data is being read then
we get a second iteration of the loop in mmci_pio_read.
However host->size is not updated until after mmci_pio_read returns,
so we get count = number of new bytes PLUS number of bytes already
copied in the first iteration. This results in a FIFO underrun as
we try and read mode data than is available.
The fix is to compensating for data read on previous iterations
when calculating the amount of data in the FIFO.
Signed-off-by: Linus Walleij <triad@df.lth.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Do a full scan of the directory to try and be a bit more proactive,
instead of waiting for things to break.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Using weight32() to determine if a value is a power of 2 is a rather
heavi weight solution. The classic idiom is (x & (x - 1)) == 0, but
the kernel already provide a is_power_of_2 function for it.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
