Hi, On 1/6/21 9:38 PM, Alex Deucher wrote: > On Wed, Jan 6, 2021 at 3:04 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >> >> Hi, >> >> On 1/6/21 8:33 PM, Alex Deucher wrote: >>> On Wed, Jan 6, 2021 at 1:10 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >>>> >>>> Hi, >>>> >>>> On 1/6/21 6:07 PM, Alex Deucher wrote: >>>>> On Wed, Jan 6, 2021 at 11:25 AM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >>>>>> >>>>>> Hi All, >>>>>> >>>>>> I get Cc-ed on all Fedora kernel bugs and this one stood out to me: >>>>>> >>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1911763 >>>>>> >>>>>> Since I've done a lot of work on the acpi-video code I thought I should >>>>>> take a look. I've managed to help the user with a kernel-commandline >>>>>> option which stops video.ko (the acpi-video kernel module) from emitting >>>>>> key-press events for ACPI_VIDEO_NOTIFY_PROBE events. >>>>>> >>>>>> This is on a Dell Vostro laptop with i915/radeon hybrid gfx. >>>>>> >>>>>> I was thinking about adding a DMI quirk for this, but from the brief time >>>>>> that I worked on nouveau (and specifically hybrid gfx setups) I know that >>>>>> these events get fired on hybrid gfx setups when the discrete GPU is >>>>>> powered down and something happens which requires the discrete GPUs drivers >>>>>> attention, like an external monitor being plugged into a connector handled >>>>>> by the dGPU (note that is not the case here). >>>>>> >>>>>> So I took a quick look at the radeon code and the radeon_atif_handler() >>>>>> function from drivers/gpu/drm/radeon/radeon_acpi.c. When successful that >>>>>> returns NOTIFY_BAD which suppresses the key-press. >>>>>> >>>>>> But in various cases it returns NOTIFY_DONE instead which does not >>>>>> suppress the key-press event. So I think that the spurious key-press events >>>>>> which the user is seeing should be avoided by this function returning >>>>>> NOTIFY_BAD. >>>>>> >>>>>> Specifically I'm wondering if we should not return >>>>>> NOTIFY_BAD when count == 0? I guess this can cause problems if there >>>>>> are multiple GPUs, but we could check if the acpi-event is for the >>>>>> pci-device the radeon driver is bound to. This would require changing the >>>>>> acpi-notify code to also pass the acpi_device pointer as part of the >>>>>> acpi_bus_event but that should not be a problem. >>>>>> >>>>> >>>>> For A+A PX/HG systems, we'd want the notifications for both the dGPU >>>>> and the APU since some of the events are relevant to one or the other. >>>>> ATIF_DGPU_DISPLAY_EVENT is only relevant to the dGPU, while >>>>> ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST would be possibly relevant to >>>>> both (if there was a mux), but mainly the APU. >>>>> ATIF_SYSTEM_POWER_SOURCE_CHANGE_REQUEST would be relevant to both. >>>>> The other events have extended bits to determine which GPU the event >>>>> is targeted at. >>>> >>>> Right, but AFAIK on hybrid systems there are 2 ACPI video-bus devices, >>>> one for each of the iGPU and dGPU which is why I suggested passing >>>> the video-bus acpi_device as extra data in acpi_bus_event and then >>>> radeon_atif_handler() could check if the acpi_device is the companion >>>> device of the GPU. This assumes that events for GPU# will also >>>> originate from (through an ACPI ASL notify call) the ACPI video-bus >>>> which belongs to that GPU. >>> >>> That's not the case. For PX/HG systems, ATIF is in the iGPU's >>> namespace, on dGPU only systems, ATIF is in the dGPU's namespace. >> >> That assumes and AMD iGPU + AMD dGPU I believe ? The system on >> which the spurious ACPI_VIDEO_NOTIFY_PROBE events lead to spurious >> KEY_SWITCHVIDEOMODE key-presses being reported uses an Intel iGPU >> with an AMD dGPU. I don't have any hybrid gfx systems available for >> testing atm, but I believe that in this case there will be 2 ACPI >> video-busses, one for each GPU. > > I think the ATIF method will be on the iGPU regardless of whether it's > intel or AMD. Ok. >> Note I'm not saying that that means that checking the originating >> ACPI device is the companion of the GPUs PCI-device is the solution >> here. But so far all I've heard from you is that that is not the >> solution, without you offering any alternative ideas / possible >> solutions to try for filtering out these spurious key-presses. > > Sorry, I'm not really an ACPI expert. I think returning NOTIFY_BAD is > fine for this specific case, but I don't know if it will break other > platforms. Yes, I'm worried too that it might break other platforms, so that option is of the table then. > That said, I don't recall seeing any other similar bugs, > so maybe this is something specific to this particular laptop. Ok, the acpi_video.c code already has the option to suppress key-press reporting based on either a cmdline option, or a DMI quirk and the reporter of the issue has already confirmed that the kernel cmdline option works around this. So I will submit a patch for acpi_video.c to add a DMI quirk for this then. This seems more of a workaround then a real solution, but it looks like this is the best which we can do atm. Regards, Hans _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
