Messages in this thread | | | Date | Tue, 28 Nov 2023 08:27:57 -0600 | Subject | Re: [RFT][PATCH v1] ACPI: OSL: Use a threaded interrupt handler for SCI | From | Mario Limonciello <> |
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On 11/27/2023 13:57, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > In the current arrangement, all of the acpi_ev_sci_xrupt_handler() code > is run as an interrupt handler for the SCI, in interrupt context. Among > other things, this causes it to run with local interrupts off which > can be problematic if many GPEs are enabled and they are located in the > I/O address space, for example (because in that case local interrupts > will be off for the duration of all of the GPE hardware accesses carried > out while handling an SCI combined and that may be quite a bit of time > in extreme scenarios). > > However, there is no particular reason why the code in question really > needs to run in interrupt context and in particular, it has no specific > reason to run with local interrupts off. The only real requirement is > to prevent multiple instences of it from running in parallel with each > other, but that can be achieved regardless. > > For this reason, use request_threaded_irq() instead of request_irq() for > the ACPI SCI and pass IRQF_ONESHOT to it in flags to indicate that the > interrupt needs to be masked while its handling thread is running so as > to prevent it from re-triggering while it is being handled (and in > particular until the final handled/not handled outcome is determined). > > While at it, drop a redundant local variable from acpi_irq(). > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > > The code inspection and (necessarily limited) testing carried out by me > are good indications that this should just always work, but there may > be still some really odd platform configurations I'm overlooking, so if > you have a way to give it a go, please do so.
Thanks for looping me in.
I tested it on a few different laptops I have on hand from different SoC generations and manufacturers and ensured that SCI was working correctly for usage and wakeup. My base kernel was 6.7-rc3 plus some unrelated RTC timeout handling patches.
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
> > --- > drivers/acpi/osl.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > Index: linux-pm/drivers/acpi/osl.c > =================================================================== > --- linux-pm.orig/drivers/acpi/osl.c > +++ linux-pm/drivers/acpi/osl.c > @@ -544,11 +544,7 @@ acpi_os_predefined_override(const struct > > static irqreturn_t acpi_irq(int irq, void *dev_id) > { > - u32 handled; > - > - handled = (*acpi_irq_handler) (acpi_irq_context); > - > - if (handled) { > + if ((*acpi_irq_handler)(acpi_irq_context)) { > acpi_irq_handled++; > return IRQ_HANDLED; > } else { > @@ -582,7 +578,8 @@ acpi_os_install_interrupt_handler(u32 gs > > acpi_irq_handler = handler; > acpi_irq_context = context; > - if (request_irq(irq, acpi_irq, IRQF_SHARED, "acpi", acpi_irq)) { > + if (request_threaded_irq(irq, NULL, acpi_irq, IRQF_SHARED | IRQF_ONESHOT, > + "acpi", acpi_irq)) { > pr_err("SCI (IRQ%d) allocation failed\n", irq); > acpi_irq_handler = NULL; > return AE_NOT_ACQUIRED; > > >
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