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df9541a60a
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> |
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| .. | ||
| devres.c | ||
| gpio-74x164.c | ||
| gpio-ab8500.c | ||
| gpio-adp5520.c | ||
| gpio-adp5588.c | ||
| gpio-bt8xx.c | ||
| gpio-cs5535.c | ||
| gpio-da9052.c | ||
| gpio-davinci.c | ||
| gpio-ep93xx.c | ||
| gpio-ge.c | ||
| gpio-generic.c | ||
| gpio-it8761e.c | ||
| gpio-janz-ttl.c | ||
| gpio-ks8695.c | ||
| gpio-langwell.c | ||
| gpio-lpc32xx.c | ||
| gpio-max730x.c | ||
| gpio-max732x.c | ||
| gpio-max7300.c | ||
| gpio-max7301.c | ||
| gpio-mc9s08dz60.c | ||
| gpio-mc33880.c | ||
| gpio-mcp23s08.c | ||
| gpio-ml-ioh.c | ||
| gpio-mpc8xxx.c | ||
| gpio-mpc5200.c | ||
| gpio-msm-v1.c | ||
| gpio-msm-v2.c | ||
| gpio-mxc.c | ||
| gpio-mxs.c | ||
| gpio-nomadik.c | ||
| gpio-omap.c | ||
| gpio-pca953x.c | ||
| gpio-pcf857x.c | ||
| gpio-pch.c | ||
| gpio-pl061.c | ||
| gpio-pxa.c | ||
| gpio-rdc321x.c | ||
| gpio-sa1100.c | ||
| gpio-samsung.c | ||
| gpio-sch.c | ||
| gpio-sodaville.c | ||
| gpio-stmpe.c | ||
| gpio-sx150x.c | ||
| gpio-tc3589x.c | ||
| gpio-tegra.c | ||
| gpio-timberdale.c | ||
| gpio-tnetv107x.c | ||
| gpio-tps65910.c | ||
| gpio-tps65912.c | ||
| gpio-twl4030.c | ||
| gpio-ucb1400.c | ||
| gpio-vr41xx.c | ||
| gpio-vx855.c | ||
| gpio-wm831x.c | ||
| gpio-wm8350.c | ||
| gpio-wm8994.c | ||
| gpio-xilinx.c | ||
| gpiolib.c | ||
| Kconfig | ||
| Makefile | ||