This patch prevent to schedule while atomic by changing the
flchip_shared spinlock into a mutex. This should be save since no atomic
path will use this lock.
It was suggested by Arnd Bergmann and Vasiliy Kulikov.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The use of a memcpy() during a spinlock operation will cause very long
thread context switch delays if the flash chip bandwidth is low and the
data to be copied large, because a spinlock will disable preemption.
For example: A flash with 6,5 MB/s bandwidth will cause under ubifs,
which request sometimes 128 KiB (the flash erase size), a preemption delay of
20 milliseconds. High priority threads will not be served during this
time, regardless whether this threads access the flash or not. This behavior
breaks real time.
The patch changes all the use of spin_lock operations for xxxx->mutex
into mutex operations, which is exact what the name says and means.
I have checked the code of the drivers and there is no use of atomic
pathes like interrupt or timers. The mtdoops facility will also not be used
by this drivers. So it is dave to replace the spin_lock against mutex.
There is no performance regression since the mutex is normally not
acquired.
Changelog:
06.03.2010 First release
26.03.2010 Fix mutex[1] issue and tested it for compile failure
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Add support for multiblock erase command. OneNANDs (excluding Flex-OneNAND)
are capable of simultaneous erase of up to 64 eraseblocks which is much faster.
This changes the erase requests for regions covering multiple eraseblocks
to be performed using multiblock erase.
Signed-off-by: Mika Korhonen <ext-mika.2.korhonen@nokia.com>
Reviewed-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
nand.h, onenand.h and flashchip.h defined enumeration types
for chip status using the same symbolic names. This prevented
a board file to include more than one of them. In particular,
no nand and onenand platform devices could live in the same file.
This patch augments flashchip.h with a few status values in order
to cover all cases, so nand.h and onenand.h can use flstate_t
without declaring their own status enum.
Signed-off-by: Alessandro Rubini <rubini@unipv.it>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Timeouts are currently given by the typical operation time times 8.
It works in the general well-behaved case but not when an erase block is
failing. For erase operations, it seems that a failing erase block will
keep the device state machine in erasing state until the vendor
specified maximum timeout period has passed. By this time the driver
would have long since timed out, left erasing state and attempted
further operations which all fail. This patch implements timeouts using
values from the CFI Query structure when available.
The patch also sets a longer timeout for locking operations. The current
value used for locking/unlocking given by 1000000/HZ microseconds is too
short for devices like J3 and J5 Strataflash which have a typical clear
lock-bits time of 0.5 seconds.
Signed-off-by: Anders Grafström <grfstrm@users.sourceforge.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Once upon a time, the MTD repository was using CVS.
This patch therefore removes all usages of the no longer updated CVS
keywords from the MTD code.
This also includes code that printed them to the user.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
When we press ctrl-alt-del,kernel_restart_prepare will invoke
cfi_intelext_reboot which will set flash to read array mode, but later
when device_shutdown is invoked which may put current work queue to
sleep and other process may be scheduled to running and programming
flash in not FL_READY mode again. So we can't boot up if this flash is
used for bootloader.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This enables support for reading, writing and locking so called
"Protection Registers" present on some flash chips.
A subset of them are pre-programmed at the factory with a
unique set of values. The rest is user-programmable.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
