linux/arch/arm/mach-dove
Russell King - ARM Linux 5d3df93542 Dove: Attempt to fix PMU/RTC interrupts
Fix the acknowledgement of PMU interrupts on Dove: some Dove hardware
has not been sensibly designed so that interrupts can be handled in a
race free manner.  The PMU is one such instance.

The pending (aka 'cause') register is a bunch of RW bits, meaning that
these bits can be both cleared and set by software (confirmed on the
Armada-510 on the cubox.)

Hardware sets the appropriate bit when an interrupt is asserted, and
software is required to clear the bits which are to be processed.  If
we write ~(1 << bit), then we end up asserting every other interrupt
except the one we're processing.  So, we need to do a read-modify-write
cycle to clear the asserted bit.

However, any interrupts which occur in the middle of this cycle will
also be written back as zero, which will also clear the new interrupts.

The upshot of this is: there is _no_ way to safely clear down interrupts
in this register (and other similarly behaving interrupt pending
registers on this device.)  The patch below at least stops us creating
new interrupts.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2012-11-21 18:25:11 +00:00
..
include/mach Merge branch 'kirkwood/addr_decode' of git://git.infradead.org/users/jcooper/linux into late/kirkwood 2012-09-22 14:22:47 -07:00
addr-map.c arm: plat-orion: use void __iomem pointers for addr-map functions 2012-09-21 18:04:47 +00:00
cm-a510.c ARM: restart: dove: use new restart hook 2012-01-05 12:57:09 +00:00
common.c ARM: dove: Add crypto engine to DT 2012-10-17 17:20:01 +00:00
common.h ARM: Dove: allow PCI to be disabled 2012-09-21 17:07:26 +00:00
dove-db-setup.c ARM: Orion: SPI: Add clk/clkdev support. 2012-05-08 16:33:55 -07:00
irq.c Dove: Attempt to fix PMU/RTC interrupts 2012-11-21 18:25:11 +00:00
Kconfig ARM: dove: add device tree based machine descriptor 2012-09-21 17:07:22 +00:00
Makefile ARM: Dove: allow PCI to be disabled 2012-09-21 17:07:26 +00:00
Makefile.boot ARM: kirkwood: move new dtbs to common Makefile 2012-09-22 14:24:00 -07:00
mpp.c arm: plat-orion: use void __iomem pointers for MPP functions 2012-09-21 18:04:24 +00:00
mpp.h ARM: dove: Consolidate mpp code with platform mpp. 2011-05-16 15:49:31 -04:00
pcie.c ARM: dove: Add pcie clock support 2012-10-17 17:19:47 +00:00