linux/arch
Hans de Goede 17e5888e4e x86: Select HARDIRQS_SW_RESEND on x86
Modern x86 laptops are starting to use GPIO pins as interrupts more
and more, e.g. touchpads and touchscreens have almost all moved away
from PS/2 and USB to using I2C with a GPIO pin as interrupt.
Modern x86 laptops also have almost all moved to using s2idle instead
of using the system S3 ACPI power state to suspend.

The Intel and AMD pinctrl drivers do not define irq_retrigger handlers
for the irqchips they register, this is causing edge triggered interrupts
which happen while suspended using s2idle to get lost.

One specific example of this is the lid switch on some devices, lid
switches used to be handled by the embedded-controller, but now the
lid open/closed sensor is sometimes directly connected to a GPIO pin.
On most devices the ACPI code for this looks like this:

Method (_E00, ...) {
	Notify (LID0, 0x80) // Status Change
}

Where _E00 is an ACPI event handler for changes on both edges of the GPIO
connected to the lid sensor, this event handler is then combined with an
_LID method which directly reads the pin. When the device is resumed by
opening the lid, the GPIO interrupt will wake the system, but because the
pinctrl irqchip doesn't have an irq_retrigger handler, the Notify will not
happen. This is not a problem in the case the _LID method directly reads
the GPIO, because the drivers/acpi/button.c code will call _LID on resume
anyways.

But some devices have an event handler for the GPIO connected to the
lid sensor which looks like this:

Method (_E00, ...) {
	if (LID_GPIO == One)
		LIDS = One
	else
		LIDS = Zero
	Notify (LID0, 0x80) // Status Change
}

And the _LID method returns the cached LIDS value, since on open we
do not re-run the edge-interrupt handler when we re-enable IRQS on resume
(because of the missing irq_retrigger handler), _LID now will keep
reporting closed, as LIDS was never changed to reflect the open status,
this causes userspace to re-resume the laptop again shortly after opening
the lid.

The Intel GPIO controllers do not allow implementing irq_retrigger without
emulating it in software, at which point we are better of just using the
generic HARDIRQS_SW_RESEND mechanism rather then re-implementing software
emulation for this separately in aprox. 14 different pinctrl drivers.

Select HARDIRQS_SW_RESEND to solve the problem of edge-triggered GPIO
interrupts not being re-triggered on resume when they were triggered during
suspend (s2idle) and/or when they were the cause of the wakeup.

This requires

 008f1d60fe ("x86/apic/vector: Force interupt handler invocation to irq context")
 c16816acd0 ("genirq: Add protection against unsafe usage of generic_handle_irq()")

to protect the APIC based interrupts from being wreckaged by a software
resend.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200123210242.53367-1-hdegoede@redhat.com
2020-03-11 22:39:39 +01:00
..
alpha Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
arc arc: mm: add p?d_leaf() definitions 2020-02-04 03:05:24 +00:00
arm More bugfixes, including a few remaining "make W=1" issues such 2020-03-01 15:16:35 -06:00
arm64 More bugfixes, including a few remaining "make W=1" issues such 2020-03-01 15:16:35 -06:00
c6x Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00
csky csky: Replace <linux/clk-provider.h> by <linux/of_clk.h> 2020-02-23 12:48:55 +08:00
h8300 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00
hexagon Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00
ia64 proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2020-02-06 08:13:23 +00:00
microblaze Microblaze patches for 5.6-rc1 2020-02-04 11:58:07 +00:00
mips MIPS: ingenic: DTS: Fix watchdog nodes 2020-02-19 10:52:35 -08:00
nds32 TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
nios2 TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
openrisc TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
parisc Merge branch 'parisc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2020-02-05 07:29:40 +00:00
powerpc powerpc/entry: Fix an #if which should be an #ifdef in entry_32.S 2020-02-19 10:35:22 +11:00
riscv riscv: adjust the indent 2020-02-24 13:12:53 -08:00
s390 s390/qdio: fill SBALEs with absolute addresses 2020-02-19 17:26:32 +01:00
sh proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
sparc Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
um proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
unicore32 MPX requires recompiling applications, which requires compiler support. 2020-01-30 16:11:50 -08:00
x86 x86: Select HARDIRQS_SW_RESEND on x86 2020-03-11 22:39:39 +01:00
xtensa Xtensa updates for v5.6: 2020-02-07 12:22:29 -08:00
.gitignore
Kconfig asm-generic/tlb: provide MMU_GATHER_TABLE_FREE 2020-02-04 03:05:26 +00:00