linux/arch
Javi Merino ee3f615819 ARM: 7136/1: pl330: Fix a race condition
If two requests have been submitted and one of them is running, if you
call pl330_chan_ctrl(ch_id, PL330_OP_START), there's a window of time
between the spin_lock_irqsave() and the _state() check in which the
running transaction may finish.  In that case, we don't receive the
interrupt (because they are disabled), but _start() sees that the DMA
is stopped, so it starts it.  The problem is that it sends the
transaction that has just finished again, because pl330_update()
hasn't mark it as done yet.

This patch fixes this race condition by not calling _start() if the
DMA is already executing transactions.  When interrupts are reenabled,
pl330_update() will call _start().

Reference: <1317892206-3600-1-git-send-email-javi.merino@arm.com>

Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Jassi Brar <jassi.brar@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-22 22:11:23 +01:00
..
alpha All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
arm ARM: 7136/1: pl330: Fix a race condition 2011-10-22 22:11:23 +01:00
avr32 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
blackfin All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
cris All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
frv All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
h8300 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
ia64 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
m32r All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
m68k All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
microblaze All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
mips All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
mn10300 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
openrisc OpenRISC: Miscellaneous 2011-07-22 18:46:41 +02:00
parisc remove remaining references to nfsservctl 2011-08-29 16:31:59 -07:00
powerpc Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2011-08-31 08:58:36 -07:00
s390 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
score modules: make arch's use default loader hooks 2011-07-24 22:06:04 +09:30
sh Merge branch 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-3.x 2011-08-29 13:34:48 -07:00
sparc sparc64: Only Panther cheetah+ chips have POPC. 2011-08-29 21:14:29 -07:00
tile Merge branch 'apei-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-08-03 21:53:27 -10:00
um ptrace: unify show_regs() prototype 2011-07-26 16:49:43 -07:00
unicore32 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2011-07-29 23:35:05 -07:00
x86 Fix pointer dereference before call to pcie_bus_configure_settings 2011-09-09 19:49:58 -07:00
xtensa All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
.gitignore
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00