genirq: Restore trigger settings in irq_modify_status()
authorMarc Zyngier <marc.zyngier@arm.com>
Fri, 18 Aug 2017 09:53:45 +0000 (10:53 +0100)
committerThomas Gleixner <tglx@linutronix.de>
Fri, 18 Aug 2017 10:04:14 +0000 (12:04 +0200)
commite8f241893dfbbebe2813c01eac54f263e6a5e59c
tree756b308ef749eb12bc0b6011d301f3d272ce0d62
parent7374bfb82e3844abcc5a5b8034620d80b92b820d
genirq: Restore trigger settings in irq_modify_status()

irq_modify_status starts by clearing the trigger settings from
irq_data before applying the new settings, but doesn't restore them,
leaving them to IRQ_TYPE_NONE.

That's pretty confusing to the potential request_irq() that could
follow. Instead, snapshot the settings before clearing them, and restore
them if the irq_modify_status() invocation was not changing the trigger.

Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Reported-and-tested-by: jeffy <jeffy.chen@rock-chips.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818095345.12378-1-marc.zyngier@arm.com
kernel/irq/chip.c