linux/drivers
Daniel Vetter 58bf8062d0 drm/i915: rip out the PM_IIR WARN
After banging my head against this for the past few months, I still
don't see how this could possible race under the premise that once an
irq bit is masked in PM_IMR and reset in PM_IIR it won't show up again
until we unmask it in PM_IMR.

Still, we have reports of this being seen in the wild. Now Bspec has
this little bit of lovely language in the PMIIR register:

Public SNB Docs, Vol3Part2, 2.5.14 "PMIIR":

"For each bit, the IIR can store a second pending interrupt if two or
more of the same interrupt conditions occur before the first condition
is cleared. Upon clearing the interrupt, the IIR bit will momentarily
go low, then return high to indicate there is another interrupt
pending."

Now if we presume that PMIMR only prevent new interrupts from being
queued, we could easily end up masking an interrupt and clearing it,
but the 2nd pending interrupt setting the bit in PMIIR right away
again. Which leads, the next time the irq handler runs, to hitting the
WARN.

Also, no bad side effects of this have ever been reported. And we've
tracked down our issues with the gpu turbo getting stuck to bogus
interrupt generation limits in th RPLIMIT register.

So let's just rip out this WARN as bogus and call it a day. The only
shallow thing here is that this 2-deep irq queue in the hw makes you
wonder how racy the windows irq handler is ...

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42907
Cc: stable@vger.kernel.org
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-06-23 00:01:41 +02:00
..
accessibility
acpi Merge branches 'bugfix-battery', 'bugfix-misc', 'bugfix-rafael', 'bugfix-turbostat', 'bugfix-video' and 'workaround-pss' into release 2012-06-04 00:48:41 -04:00
amba arm-soc: driver specific updates 2012-05-26 12:22:27 -07:00
ata Viresh has moved 2012-06-20 14:39:36 -07:00
atm solos-pci: Fix DMA support 2012-05-24 16:22:53 -04:00
auxdisplay
base Driver core and printk fixes for 3.5-rc4 2012-06-20 15:14:28 -07:00
bcma bcma: fix null pointer in bcma_core_pci_irq_ctl 2012-06-08 13:47:07 -04:00
block mtip32xx: Changes to sysfs entries 2012-05-31 08:46:50 +02:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-05-24 11:54:29 -07:00
cdrom
char Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-06-18 12:20:36 -07:00
clk Viresh has moved 2012-06-20 14:39:36 -07:00
clocksource clocksource: sh_tmu: Use clockevents_config_and_register(). 2012-06-11 17:10:16 +09:00
connector
cpufreq ARM: ux500: core U9540 support 2012-05-02 00:25:13 +02:00
cpuidle cpuidle: Use kick_all_cpus_sync() 2012-05-08 12:35:06 +02:00
crypto arm-soc: clock driver changes 2012-05-26 12:42:29 -07:00
dca
devfreq Power management updates for 3.5 2012-05-23 14:07:06 -07:00
dio
dma Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-06-20 22:12:52 -07:00
edac edac: Do alignment logic properly in edac_align_ptr() 2012-06-11 12:43:16 -03:00
eisa
extcon extcon: max8997: Add missing kfree for info->edev in max8997_muic_remove() 2012-06-18 16:30:42 -07:00
firewire IEEE 1394 (FireWire) subsystem updates post v3.4: 2012-05-24 12:57:47 -07:00
firmware efivars: Improve variable validation 2012-05-03 17:19:19 -07:00
gpio gpio/samsung: fix the typo 'exynos5_xxx' instead of 'exonys5_xxx' 2012-06-03 21:21:01 -07:00
gpu drm/i915: rip out the PM_IIR WARN 2012-06-23 00:01:41 +02:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-22 19:22:50 -07:00
hsi
hv Driver core pull for 3.5-rc1 2012-05-22 16:02:13 -07:00
hwmon hwmon fixes for 3.5-rc4 2012-06-21 13:40:40 -07:00
hwspinlock
i2c i2c: Add generic I2C multiplexer using pinctrl API 2012-06-04 16:49:43 +02:00
ide drivers/ide/ide-cs.c: adjust suspicious bit operation 2012-06-12 15:51:41 -07:00
idle
ieee802154 drivers/ieee802154: IEEE 802.15.4 loopback driver 2012-05-16 15:17:08 -04:00
iio iio: drop wrong reference from Kconfig 2012-06-14 17:28:46 -07:00
infiniband Merge branches 'cxgb4', 'mlx4' and 'ocrdma' into for-linus 2012-06-06 10:08:11 -07:00
input i2c: Split I2C_M_NOSTART support out of I2C_FUNC_PROTOCOL_MANGLING 2012-05-30 10:55:34 +02:00
iommu iommu/amd: Fix deadlock in ppr-handling error path 2012-06-04 12:47:44 +02:00
isdn Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-05-24 11:54:29 -07:00
leds leds: Make LEDS_ASIC3 and LEDS_RENESAS_TPU depend on LEDS_CLASS=y 2012-06-12 10:56:25 +08:00
lguest
macintosh powerpc/windfarm: Fix crash on SMU based machine after i2c conversion 2012-05-09 10:58:21 +10:00
md md: 2 fixes for 3.5-rc 2012-06-06 09:49:28 -07:00
media media: pms.c needs linux/slab.h 2012-06-20 22:10:08 -07:00
memory memory: tegra{20,30}-mc: Remove empty *_remove() 2012-05-14 12:52:52 -07:00
memstick
message Merge branch 'akpm' (Andrew's patch-bomb) 2012-05-31 18:10:18 -07:00
mfd Viresh has moved 2012-06-20 14:39:36 -07:00
misc misc: mei: set WDIOF_ALARMONLY on mei watchdog 2012-06-13 15:34:31 -07:00
mmc Merge branch 'akpm' (Andrew's patch-bomb) 2012-06-20 14:41:57 -07:00
mtd kmsg - kmsg_dump() use iterator to receive log buffer content 2012-06-15 14:53:59 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-06-14 15:33:55 +03:00
nfc NFC: potential integer overflow problem in check_crc() 2012-05-25 11:16:16 -04:00
nubus
of Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2012-05-29 18:27:19 -07:00
oprofile
parisc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-22 19:22:50 -07:00
parport Driver core pull for 3.5-rc1 2012-05-22 16:02:13 -07:00
pci USB: add NO_D3_DURING_SLEEP flag and revert 151b612847 2012-06-13 13:11:39 -07:00
pcmcia pcmcia: add driver for hx4700 2012-05-07 09:56:39 +08:00
pinctrl Merge branch 'akpm' (Andrew's patch-bomb) 2012-06-20 14:41:57 -07:00
platform drivers/platform/x86/acerhdf.c: correct Boris' mail address 2012-06-07 14:43:55 -07:00
pnp
power A bunch of fixes for v3.5, nothing extraordinary. 2012-05-31 12:10:15 -07:00
pps
ps3
ptp Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-22 19:22:50 -07:00
rapidio rapidio/tsi721: add DMA engine support 2012-05-31 17:49:31 -07:00
regulator regulator: Change db8500-prcmu match names to reflect Device Tree 2012-06-17 18:27:49 +01:00
remoteproc remoteproc/omap: fix dev_err typo 2012-06-17 10:31:03 +03:00
rpmsg
rtc Merge branches 'bugfix-battery', 'bugfix-misc', 'bugfix-rafael', 'bugfix-turbostat', 'bugfix-video' and 'workaround-pss' into release 2012-06-04 00:48:41 -04:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2012-05-31 10:51:10 -07:00
sbus
scsi SCSI fixes on 20120614 2012-06-15 17:39:32 -07:00
sfi
sh sh: intc: Kill off special reservation interface. 2012-05-22 19:07:55 +09:00
sn
spi SPI: fix over-eager devm_xxx() conversion 2012-06-18 11:27:04 +01:00
ssb ssb: add PCI IDs 0x4322 and 43222 2012-05-16 12:46:37 -04:00
staging staging tree fixes for 3.5-rc4 2012-06-20 15:15:03 -07:00
target target: Return error to initiator if SET TARGET PORT GROUPS emulation fails 2012-06-12 20:12:25 -07:00
tc
thermal
tty Serial driver fixes for 3.5-rc4 2012-06-20 15:13:13 -07:00
uio uio_pdrv_genirq: get irq through platform resource if not set otherwise 2012-05-15 08:44:58 -07:00
usb USB: fix gathering of interface associations 2012-06-14 17:13:34 -07:00
uwb
vhost Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-05-16 22:17:37 -04:00
video fbdev fixes for 3.5 2012-06-16 16:59:05 -07:00
virt
virtio virtio-mmio: Devices parameter parsing 2012-05-22 12:16:15 +09:30
vlynq
vme VME: Move API documentation to Documentation folder 2012-05-08 16:01:34 -07:00
w1 arm-soc: clock driver changes 2012-05-26 12:42:29 -07:00
watchdog Viresh has moved 2012-06-20 14:39:36 -07:00
xen Five bug-fixes: 2012-06-15 17:17:15 -07:00
zorro
Kconfig Staging tree pull request for 3.5-rc1 2012-05-22 16:34:21 -07:00
Makefile arm-soc: driver specific updates 2012-05-26 12:22:27 -07:00