Messages in this thread | | | Subject | Re: [PATCH] x86/hpet: Cure interface abuse in the resume path | From | "Rafael J. Wysocki" <> | Date | Tue, 1 Aug 2017 00:22:17 +0200 |
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On 7/31/2017 10:07 PM, Thomas Gleixner wrote: > The HPET resume path abuses irq_domain_[de]activate_irq() to restore the > MSI message in the HPET chip for the boot CPU on resume and it relies on an > implementation detail of the interrupt core code, which magically makes the > HPET unmask call invoked via a irq_disable/enable pair. This worked as long > as the irq code did unconditionally invoke the unmask() callback. With the > recent changes which keep track of the masked state to avoid expensive > hardware access, this does not longer work. As a consequence the HPET timer > interrupts are not unmasked which breaks resume as the boot CPU waits > forever that a timer interrupt arrives. > > Make the restore of the MSI message explicit and invoke the unmask() > function directly. While at it get rid of the pointless affinity setting as > nothing can change the affinity of the interrupt and the vector across > suspend/resume. The restore of the MSI message reestablishes the previous > affinity setting which is the correct one. > > Fixes: bf22ff45bed6 ("genirq: Avoid unnecessary low level irq function calls") > Reported-by: Martin Peres <martin.peres@linux.intel.com> > Reported-by: Tomi Sarvela <tomi.p.sarvela@intel.com> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: jeffy.chen@rock-chips.com > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Peter Ziljstra <peterz@infradead.org> > Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
ACK
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