| Message ID | 5745568.DvuYhMxLoT@kreacher (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | [RFT,v1] ACPI: OSL: Use a threaded interrupt handler for SCI | expand |
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; > > >
Hi Rafael, On Mon, Nov 27, 2023 at 08:57:43PM +0100, 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. Tried this on ADL-S and ADL-P systems that I have here and both work just fine with the patch applied. I can see SCI interrupt count increases in /proc/interrupts as expected. Did a couple of s2idle cycles too, all good. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Hi Mika, Hi Mario, On Wed, Nov 29, 2023 at 11:39 AM Mika Westerberg <mika.westerberg@linux.intel.com> wrote: > > Hi Rafael, > > On Mon, Nov 27, 2023 at 08:57:43PM +0100, 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. > > Tried this on ADL-S and ADL-P systems that I have here and both work > just fine with the patch applied. I can see SCI interrupt count > increases in /proc/interrupts as expected. Did a couple of s2idle cycles > too, all good. > > Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Thanks for your replies and tags! Given the lack of response from anyone else I'm going to move this towards linux-next with 6.8 as the target. Thank you!
On 23/11/30 02:28PM, Rafael J. Wysocki wrote: > Hi Mika, Hi Mario, > Thanks for your replies and tags! > > Given the lack of response from anyone else I'm going to move this > towards linux-next with 6.8 as the target. > > Thank you! I got a stack trace in dmesg with linux6.8-rc1 that seems to be caused by this commit according to my bisection, see the bugzilla report for details / further discussion: https://bugzilla.kernel.org/show_bug.cgi?id=218407 Cheers, Christian
On Tue, Jan 23, 2024 at 5:39 PM Christian Heusel <christian@heusel.eu> wrote: > > On 23/11/30 02:28PM, Rafael J. Wysocki wrote: > > Hi Mika, Hi Mario, > > Thanks for your replies and tags! > > > > Given the lack of response from anyone else I'm going to move this > > towards linux-next with 6.8 as the target. > > > > Thank you! > > I got a stack trace in dmesg with linux6.8-rc1 that seems to be caused > by this commit according to my bisection, see the bugzilla report for > details / further discussion: > > https://bugzilla.kernel.org/show_bug.cgi?id=218407 Mario's suggestion to add IRQF_ONESHOT to pinctrl-amd in amd_gpio_probe() looks right to me.
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;