From bb68cfe2f5a7f43058aed299fdbb73eb281734ed Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 31 Jul 2017 22:07:09 +0200 Subject: x86/hpet: Cure interface abuse in the resume path 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-and-tested-by: Tomi Sarvela Reported-by: Martin Peres Signed-off-by: Thomas Gleixner Acked-by: "Rafael J. Wysocki" Cc: jeffy.chen@rock-chips.com Cc: Peter Zijlstra Cc: Marc Zyngier Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1707312158590.2287@nanos --- arch/x86/kernel/hpet.c | 27 +++++++++++---------------- 1 file changed, 11 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 16f82a3aaec7..8ce4212e2b8d 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -345,21 +345,10 @@ static int hpet_shutdown(struct clock_event_device *evt, int timer) return 0; } -static int hpet_resume(struct clock_event_device *evt, int timer) -{ - if (!timer) { - hpet_enable_legacy_int(); - } else { - struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); - - irq_domain_deactivate_irq(irq_get_irq_data(hdev->irq)); - irq_domain_activate_irq(irq_get_irq_data(hdev->irq)); - disable_hardirq(hdev->irq); - irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu)); - enable_irq(hdev->irq); - } +static int hpet_resume(struct clock_event_device *evt) +{ + hpet_enable_legacy_int(); hpet_print_config(); - return 0; } @@ -417,7 +406,7 @@ static int hpet_legacy_set_periodic(struct clock_event_device *evt) static int hpet_legacy_resume(struct clock_event_device *evt) { - return hpet_resume(evt, 0); + return hpet_resume(evt); } static int hpet_legacy_next_event(unsigned long delta, @@ -510,8 +499,14 @@ static int hpet_msi_set_periodic(struct clock_event_device *evt) static int hpet_msi_resume(struct clock_event_device *evt) { struct hpet_dev *hdev = EVT_TO_HPET_DEV(evt); + struct irq_data *data = irq_get_irq_data(hdev->irq); + struct msi_msg msg; - return hpet_resume(evt, hdev->num); + /* Restore the MSI msg and unmask the interrupt */ + irq_chip_compose_msi_msg(data, &msg); + hpet_msi_write(hdev, &msg); + hpet_msi_unmask(data); + return 0; } static int hpet_msi_next_event(unsigned long delta, -- cgit v1.2.3-58-ga151