linux/kernel/irq
Rafael J. Wysocki c2ddeb2961 genirq: Introduce IRQF_COND_ONESHOT and use it in pinctrl-amd
There is a problem when a driver requests a shared interrupt line to run a
threaded handler on it without IRQF_ONESHOT set if that flag has been set
already for the IRQ in question by somebody else.  Namely, the request
fails which usually leads to a probe failure even though the driver might
have worked just fine with IRQF_ONESHOT, but it does not want to use it by
default.  Currently, the only way to handle this is to try to request the
IRQ without IRQF_ONESHOT, but with IRQF_PROBE_SHARED set and if this fails,
try again with IRQF_ONESHOT set.  However, this is a bit cumbersome and not
very clean.

When commit 7a36b901a6 ("ACPI: OSL: Use a threaded interrupt handler for
SCI") switched the ACPI subsystem over to using a threaded interrupt
handler for the SCI, it had to use IRQF_ONESHOT for it because that's
required due to the way the SCI handler works (it needs to walk all of the
enabled GPEs before the interrupt line can be unmasked). The SCI interrupt
line is not shared with other users very often due to the SCI handling
overhead, but on sone systems it is shared and when the other user of it
attempts to install a threaded handler, a flags mismatch related to
IRQF_ONESHOT may occur.

As it turned out, that happened to the pinctrl-amd driver and so commit
4451e8e841 ("pinctrl: amd: Add IRQF_ONESHOT to the interrupt request")
attempted to address the issue by adding IRQF_ONESHOT to the interrupt
flags in that driver, but this is now causing an IRQF_ONESHOT-related
mismatch to occur on another system which cannot boot as a result of it.

Clearly, pinctrl-amd can work with IRQF_ONESHOT if need be, but it should
not set that flag by default, so it needs a way to indicate that to the
interrupt subsystem.

To that end, introdcuce a new interrupt flag, IRQF_COND_ONESHOT, which will
only have effect when the IRQ line is shared and IRQF_ONESHOT has been set
for it already, in which case it will be promoted to the latter.

This is sufficient for drivers sharing the interrupt line with the SCI as
it is requested by the ACPI subsystem before any drivers are probed, so
they will always see IRQF_ONESHOT set for the interrupt in question.

Fixes: 4451e8e841 ("pinctrl: amd: Add IRQF_ONESHOT to the interrupt request")
Reported-by: Francisco Ayala Le Brun <francisco@videowindow.eu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: 6.8+ <stable@vger.kernel.org> # 6.8+
Closes: https://lore.kernel.org/lkml/CAN-StX1HqWqi+YW=t+V52-38Mfp5fAz7YHx4aH-CQjgyNiKx3g@mail.gmail.com/
Link: https://lore.kernel.org/r/12417336.O9o76ZdvQC@kreacher
2024-03-25 23:45:21 +01:00
..
affinity.c genirq/affinity: Move group_cpus_evenly() into lib/ 2023-01-17 18:50:06 +01:00
autoprobe.c genirq: Delay deactivation in free_irq() 2019-07-03 10:12:28 +02:00
chip.c genirq: Prevent nested thread vs synchronize_hardirq() deadlock 2023-07-31 17:24:22 +02:00
cpuhotplug.c sched/isolation: Use single feature type while referring to housekeeping cpumask 2022-02-16 15:57:55 +01:00
debug.h Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
debugfs.c x86/apic/msi: Fix misconfigured non-maskable MSI quirk 2023-10-26 13:53:06 +02:00
devres.c genirq/devres: Use struct_size() in devm_kzalloc() 2019-04-16 21:54:03 +02:00
dummychip.c irq: Fix typos in comments 2021-03-22 04:23:14 +01:00
generic-chip.c genirq/generic_chip: Make irq_remove_generic_chip() irqdomain aware 2023-10-27 09:15:44 +02:00
handle.c irq: remove unused flags argument from __handle_irq_event_percpu() 2022-01-07 00:25:25 +01:00
internals.h genirq: Remove unused extern declaration 2023-07-31 17:27:16 +02:00
ipi-mux.c genirq/ipi-mux: Use irq_domain_alloc_irqs() 2023-02-06 17:21:15 +00:00
ipi.c genirq/ipi: Fix NULL pointer deref in irq_data_get_affinity_mask() 2023-02-20 13:53:41 +01:00
irq_sim.c genirq/irq_sim: Shrink code by using <linux/cleanup.h> helpers 2024-01-29 11:07:57 +01:00
irqdesc.c genirq: Deduplicate interrupt descriptor initialization 2024-01-24 16:02:48 +01:00
irqdomain.c genirq/irqdomain: Don't call ops->select for DOMAIN_BUS_ANY tokens 2024-02-20 17:30:57 +01:00
Kconfig genirq: Add mechanism to multiplex a single HW IPI 2023-02-05 10:57:55 +00:00
Makefile genirq: Add mechanism to multiplex a single HW IPI 2023-02-05 10:57:55 +00:00
manage.c genirq: Introduce IRQF_COND_ONESHOT and use it in pinctrl-amd 2024-03-25 23:45:21 +01:00
matrix.c genirq/matrix: Dynamic bitmap allocation 2024-02-23 10:18:44 +01:00
migration.c genirq: Fix typos and misspellings in comments 2021-03-16 15:08:29 +01:00
msi.c genirq/msi: Provide MSI_FLAG_PARENT_PM_DEV 2024-02-15 17:55:41 +01:00
pm.c genirq/PM: Unexport {suspend,resume}_device_irqs() 2022-06-13 12:27:37 +02:00
proc.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
resend.c genirq: Fix software resend lockup and nested resend 2023-08-26 19:14:31 +02:00
settings.h genirq: Add a IRQF_NO_DEBUG flag 2021-05-17 20:01:35 +02:00
spurious.c genirq: Disable irqfixup/poll on PREEMPT_RT. 2021-09-19 23:01:15 +02:00
timings.c Updates to the interrupt core and driver subsystems: 2021-08-30 14:38:37 -07:00