linux/arch/arm
Jon Hunter 77da2d910a OMAP3: PM: Prevent hang in prcm_interrupt_handler
There are two scenarios where a race condition could result in a hang
in the prcm_interrupt handler. These are:

1). Waiting for PRM_IRQSTATUS_MPU register to clear.
Bit 0 of the PRM_IRQSTATUS_MPU register indicates that a wake-up event
is pending for the MPU. This bit can only be cleared if the all the
wake-up events latched in the various PM_WKST_x registers have been
cleared. If a wake-up event occurred during the processing of the prcm
interrupt handler, after the corresponding PM_WKST_x register was
checked but before the PRM_IRQSTATUS_MPU was cleared, then the CPU
would be stuck forever waiting for bit 0 in PRM_IRQSTATUS_MPU to be
cleared.

2). Waiting for the PM_WKST_x register to clear.
Some power domains have more than one wake-up source. The PM_WKST_x
registers indicate the source of a wake-up event and need to be cleared
after a wake-up event occurs. When the PM_WKST_x registers are read and
before they are cleared, it is possible that another wake-up event
could occur causing another bit to be set in one of the PM_WKST_x
registers. If this did occur after reading a PM_WKST_x register then
the CPU would miss this event and get stuck forever in a loop waiting
for that PM_WKST_x register to clear.

This patch address the above race conditions that would result in a
hang.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2009-10-05 10:50:59 -07:00
..
boot kbuild: use INSTALLKERNEL to select customized installkernel script 2009-09-20 12:18:14 +02:00
common Merge branch 'master' into for-linus 2009-09-22 21:01:40 +01:00
configs Merge branch 'origin' into for-linus 2009-09-24 21:22:33 +01:00
include/asm Merge branch 'origin' into for-linus 2009-09-24 21:22:33 +01:00
kernel make Linux bootable on ARM again 2009-09-26 10:06:53 -07:00
lib Merge branch 'for-rmk' of git://linux-arm.org/linux-2.6 2009-09-19 13:47:57 +01:00
mach-aaec2000
mach-at91 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2009-09-25 07:22:11 -07:00
mach-bcmring ARM: 5642/1: bcmring: add Makefile/Kconfig/Makefile.boot in mach-bcmring 2009-08-15 16:01:50 +01:00
mach-clps711x
mach-davinci DaVinci: DM646x - platform changes for vpif capture and display drivers 2009-09-16 10:28:46 -07:00
mach-ebsa110
mach-ep93xx ep93xx video driver platform support 2009-09-23 07:39:51 -07:00
mach-footbridge
mach-gemini Gemini: Fix SRAM/ROM location after memory swap 2009-05-28 16:42:25 +03:00
mach-h720x
mach-integrator ARM: 5720/1: Move MMCI header to amba include dir 2009-09-22 20:49:04 +01:00
mach-iop13xx Merge branch 'iop-raid6' into async-tx-next 2009-09-08 17:53:57 -07:00
mach-iop32x
mach-iop33x
mach-ixp4xx ixp4xx: arch_idle() documentation fixup 2009-09-21 19:20:03 +02:00
mach-ixp23xx
mach-ixp2000
mach-kirkwood Merge branch 'master' into devel 2009-09-12 12:04:37 +01:00
mach-ks8695 ARM: 5637/1: [KS8695] Don't reference CLOCK_TICK_RATE in drivers 2009-08-05 22:06:56 +01:00
mach-l7200 [ARM] mach-l7200: fix spelling of SYS_CLOCK_OFF 2009-05-18 11:25:08 +01:00
mach-lh7a40x
mach-loki [ARM] add coherent DMA mask for mv643xx_eth 2009-05-22 17:05:53 -04:00
mach-mmp [ARM] pxa: add PWM devices support for pxa168/910 2009-06-05 10:32:06 +08:00
mach-msm
mach-mv78xx0 [ARM] orion: convert gpio to use gpiolib 2009-06-08 13:04:57 -04:00
mach-mx1 ARM: mxc: Fix i2c_board_info definitions 2009-08-14 12:40:37 +02:00
mach-mx2 mx21ads: Fix framebuffer platform data 2009-08-14 12:41:16 +02:00
mach-mx3 Merge branch 'master' into devel 2009-09-12 12:04:37 +01:00
mach-mx25 Freescale i.MX25 PDK (3ds) board support 2009-08-14 12:40:43 +02:00
mach-mxc91231 MXC: add iomux pins configuration support for MXC91231 2009-08-14 12:40:47 +02:00
mach-netx netx: Use get_irqnr_preamble to initialize base register 2009-08-13 20:34:36 +02:00
mach-nomadik mtd: OneNand support for Nomadik 8815 SoC (on NHK8815 board) 2009-09-20 06:00:27 -07:00
mach-ns9xxx
mach-omap1 OMAP1: AMS_DELTA: add modem support 2009-08-28 10:51:37 -07:00
mach-omap2 OMAP3: PM: Prevent hang in prcm_interrupt_handler 2009-10-05 10:50:59 -07:00
mach-orion5x [ARM] orion5x: Add LaCie NAS 2Big Network support 2009-09-08 14:10:35 -04:00
mach-pnx4008
mach-pxa Merge branch 'master' into for-linus 2009-09-22 21:01:40 +01:00
mach-realview ARM: 5720/1: Move MMCI header to amba include dir 2009-09-22 20:49:04 +01:00
mach-rpc
mach-s3c24a0/include/mach ARM: S3C: move s3c_device_nand from plat-s3c24xx to plat-s3c 2009-07-31 00:10:24 +01:00
mach-s3c2400 [ARM] S3C24XX: GPIO: Fix error returns from gpio functions 2009-05-18 19:40:18 +01:00
mach-s3c2410 ARM: S3C: Add missing selection of S3C_DEV_NAND in machine Kconfigs. 2009-09-17 10:12:28 +01:00
mach-s3c2412 ARM: S3C: Add missing selection of S3C_DEV_NAND in machine Kconfigs. 2009-09-17 10:12:28 +01:00
mach-s3c2440 ARM: S3C: Add missing selection of S3C_DEV_NAND in machine Kconfigs. 2009-09-17 10:12:28 +01:00
mach-s3c2442 [ARM] GTA02: build fixes (s3c2410_nand_set usage) 2009-06-24 00:10:46 +01:00
mach-s3c2443 [ARM] S3C24XX: DMA: Split hardware regs out of <mach/dma.h> 2009-05-01 11:39:06 +01:00
mach-s3c6400 ARM: S3C: Add missing selection of S3C_DEV_NAND in machine Kconfigs. 2009-09-17 10:12:28 +01:00
mach-s3c6410 ARM: S3C: Add missing selection of S3C_DEV_NAND in machine Kconfigs. 2009-09-17 10:12:28 +01:00
mach-s5pc100 ARM: S5PC100: Board and configuration file 2009-08-16 23:40:39 +01:00
mach-sa1100 ARM: 5712/1: SA1100: initialise spinlock in DMA code 2009-09-20 12:55:49 +01:00
mach-shark
mach-stmp37xx [ARM] 5539/1: Freescale STMP: onboard devices declaration 2009-06-04 14:16:45 +01:00
mach-stmp378x [ARM] 5539/1: Freescale STMP: onboard devices declaration 2009-06-04 14:16:45 +01:00
mach-u300 ARM: 5720/1: Move MMCI header to amba include dir 2009-09-22 20:49:04 +01:00
mach-versatile ARM: 5720/1: Move MMCI header to amba include dir 2009-09-22 20:49:04 +01:00
mach-w90x900 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2009-09-14 17:56:51 -07:00
mm Merge branch 'origin' into for-linus 2009-09-24 21:22:33 +01:00
nwfpe [ARM] nwfpe: fix 'floatx80_is_nan' sparse warning 2009-05-15 12:49:14 +01:00
oprofile RealView: Move the IRQ_* definitions out of the board-*.h files 2009-05-30 14:00:17 +01:00
plat-iop Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx into for-linus 2009-09-23 18:31:11 +10:00
plat-mxc spi: add SPI driver for most known i.MX SoCs 2009-09-23 07:39:43 -07:00
plat-omap Merge git://git.infradead.org/mtd-2.6 2009-09-23 10:07:49 -07:00
plat-orion [ARM] Kirkwood: __init requires linux/init.h 2009-08-24 11:55:59 -04:00
plat-pxa [ARM] pxa/dma: add debugfs entries 2009-09-10 18:49:29 +08:00
plat-s3c ARM: s3c: fix check of index into s3c_gpios[] 2009-09-19 12:14:06 +01:00
plat-s3c24xx Merge branch 'master' into devel 2009-09-12 12:04:37 +01:00
plat-s3c64xx Merge branch 'next-s3c-fixes' of git://aeryn.fluff.org.uk/bjdooks/linux 2009-09-18 20:55:56 +01:00
plat-s5pc1xx ARM: S5PC100: Kconfigs and Makefiles 2009-08-16 23:35:19 +01:00
plat-stmp3xxx ARM: STMP3xxx: deallocation with negative index of descriptors[] 2009-09-19 12:14:05 +01:00
tools [ARM] Update mach-types 2009-09-18 21:42:01 +01:00
vfp Thumb-2: Implement the unified VFP support 2009-07-24 12:32:57 +01:00
Kconfig ARM: 5580/2: ARM TCM (Tightly-Coupled Memory) support v3 2009-09-15 22:11:05 +01:00
Kconfig-nommu
Kconfig.debug Thumb-2: Add Thumb-2 support to the build files 2009-07-24 12:33:02 +01:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next 2009-09-23 15:37:02 -07:00