linux/drivers
Thomas Gleixner df9541a60a gpio: pch9: Use proper flow type handlers
Jean-Francois Dagenais reported:

 Configuring a gpio pin with the gpio-pch driver with
 "IRQF_TRIGGER_LOW | IRQF_ONESHOT" generates an interrupt storm for
 threaded ISR until the ISR thread actually gets to physically clear
 the interrupt on the triggering chip!! The immediate observable
 symptom is the high CPU usage for my ISR thread task and the
 interrupt count in /proc/interrupts incrementing radically.

The driver is wrong in several ways:

1) Using handle_simple_irq() does not provide proper flow control
   handling. In the case of oneshot threaded handlers for the
   demultiplexed interrupts this results in an interrupt storm because
   the simple handler does not deal with masking/unmasking.  Even
   without threaded oneshot handlers an interrupt storm for level type
   interrupts can easily be triggered when the interrupt is disabled
   and the interrupt line is activated from the device.

2) Acknowlegding the demultiplexed interrupt before calling the
   handler is wrong for level type interrupts.

3) The set_type function unconditionally enables the interrupt. It's
   supposed to set the type and nothing else. The unmasking is done by
   the core code.

Move the acknowledge code into a separate function and add it to the
demux irqchip callbacks.

Remove the unconditional enabling from the set_type() callback and set
the proper flow handlers depending on the selected type (level/edge).

Reported-and-tested-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-11 18:18:50 -06:00
..
accessibility
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
amba ARM: 7366/3: amba: Remove AMBA level regulator support 2012-04-13 14:04:08 +01:00
ata Change summary: 2012-05-03 17:16:52 -07:00
atm Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
auxdisplay
base drivers/base: fix compiler warning in SoC export driver - idr should be ida 2012-04-09 14:54:22 -07:00
bcma bcma: use fallback sprom if no on chip sprom is available 2012-04-16 13:32:01 -04:00
block Fixes in various components: 2012-04-20 11:31:00 -07:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2012-04-27 15:16:43 -04:00
cdrom
char tty and serial fixes for 3.4-rc2 2012-04-12 15:36:33 -07:00
clk
clocksource Revert "clocksource: Load the ACPI PM clocksource asynchronously" 2012-04-12 00:05:05 +02:00
connector
cpufreq cpufreq: OMAP: fix build errors: depends on ARCH_OMAP2PLUS 2012-04-13 17:57:40 -07:00
cpuidle Merge branches 'idle-fix' and 'misc' into release 2012-04-06 21:48:59 -04:00
crypto crypto: talitos - properly lock access to global talitos registers 2012-04-09 15:13:40 +08:00
dca
devfreq ARM: global cleanups 2012-03-27 16:03:32 -07:00
dio
dma Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
edac Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2012-04-06 17:56:20 -07:00
eisa
firewire Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
firmware efivars: Improve variable validation 2012-05-03 17:19:19 -07:00
gpio gpio: pch9: Use proper flow type handlers 2012-05-11 18:18:50 -06:00
gpu drm/radeon: clarify and extend wb setup on APUs and NI+ asics 2012-05-04 09:36:11 +01:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2012-04-20 10:39:33 -07:00
hsi HSI: hsi_char: Remove max_data_size from sysfs 2012-04-23 14:23:32 +03:00
hv
hwmon hwmon: (coretemp) Increase CPU core limit 2012-05-01 09:16:14 -07:00
hwspinlock
i2c i2c: mxs: disable QUEUE when sending is done 2012-04-27 16:13:29 +02:00
ide Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
idle simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
ieee802154
infiniband A few fixes for regressions introduced in 3.4-rc1: 2012-04-26 15:35:35 -07:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2012-04-30 10:13:48 -07:00
iommu Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
isdn tty and serial fixes for 3.4-rc2 2012-04-12 15:36:33 -07:00
leds leds-atmel-pwm.c: Make pwmled_probe() __devinit 2012-04-17 16:29:31 +02:00
lguest
macintosh Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
mca
md md/bitmap: fix calculation of 'chunks' - missing shift. 2012-05-04 17:03:18 +10:00
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-04-21 12:43:23 -07:00
memstick
message Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
mfd mfd: Fix build breakage in omap-usb-host.c 2012-05-01 11:55:04 +02:00
misc Merge branch 'akpm' (Andrew's patch-bomb) 2012-04-05 15:30:34 -07:00
mmc Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
mtd Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-04-26 15:33:36 -07:00
net sungem: Fix WakeOnLan 2012-05-03 01:42:55 -04:00
nfc
nubus Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
of gpio: Fix range check in of_gpio_simple_xlate() 2012-04-10 14:20:56 -06:00
oprofile simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
parisc Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
parport
pci Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
pcmcia Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia 2012-03-29 16:00:48 -07:00
pinctrl pinctrl: implement pinctrl_check_ops 2012-04-11 09:31:02 +02:00
platform Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-06 12:19:38 -07:00
pnp Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-03-30 16:45:39 -07:00
power Various small bugfixes and enhancements, plus two new drivers: 2012-03-30 16:09:02 -07:00
pps
ps3
ptp
rapidio
regulator regulator: Fix a build warning in the anatop driver for 3.4 2012-04-10 10:26:41 -07:00
remoteproc simple_open: automatically convert to simple_open() 2012-04-05 15:25:50 -07:00
rpmsg
rtc Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-04 15:35:09 -07:00
s390 qeth: Use blkt defaults for OSA Express 4 2012-04-24 00:33:17 -04:00
sbus Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
scsi [SCSI] libfc: update mfs boundry checking 2012-04-25 08:46:29 +01:00
sfi
sh SuperH updates for 3.4 merge window 2012-03-30 00:09:17 -07:00
sn
spi spi/spi-bfin5xx: Fix flush of last bit after each spi transfer 2012-04-27 12:20:39 -06:00
ssb
staging staging: ozwpan: Fix bug where kfree is called twice. 2012-04-26 12:40:53 -07:00
target tcm_fc: Do not free tpg structure during wq allocation failure 2012-04-06 18:57:05 -07:00
tc
thermal
tty TTY fix for 3.4-rc5 2012-05-02 13:47:49 -07:00
uio
usb USB: ehci-tegra: remove redundant gpio_set_value 2012-05-01 14:11:51 -04:00
uwb uwb: fix error handling 2012-04-18 13:15:51 -07:00
vhost Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-04-22 21:02:57 -07:00
video blackfin: fix compile error in bfin-lq035q1-fb.c 2012-04-26 14:46:51 -04:00
virt
virtio virtio_balloon: fix handling of PAGE_SIZE != 4k 2012-04-15 11:51:06 +03:00
vlynq
w1
watchdog hpwdt: Only BYTE reads/writes to WD Timer port 0x72 2012-04-26 14:38:07 +02:00
xen xen/acpi: Workaround broken BIOSes exporting non-existing C-states. 2012-04-26 22:07:28 -04:00
zorro
Kconfig Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi 2012-04-02 09:50:40 -07:00
Makefile Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi 2012-04-02 09:50:40 -07:00