On Fri, Apr 23, 2021 at 8:41 PM Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > On Fri, Apr 23, 2021 at 12:46:54PM +0800, Kai-Heng Feng wrote: > > On HP Fury G7 Workstations, graphics output is re-routed from Intel GFX > > to discrete GFX after S3. This is not desirable, because userspace will > > treat connected display as a new one, losing display settings. > > > > The expected behavior is to let discrete GFX drives all external > > displays. > > > > The platform in question uses ACPI method \_SB.PCI0.HGME to enable MUX. > > The method is inside the BXT _DSM, so add the _DSM and call it > > accordingly. > > > > I also tested some MUX-less and iGPU only laptops with the BXT _DSM, no > > regression was found. > > > > v2: > > - Forward declare struct pci_dev. > > > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3113 > > References: https://lore.kernel.org/intel-gfx/1460040732-31417-4-git-send-email-animesh.manna@xxxxxxxxx/ > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > > --- > > drivers/gpu/drm/i915/display/intel_acpi.c | 17 +++++++++++++++++ > > drivers/gpu/drm/i915/display/intel_acpi.h | 3 +++ > > drivers/gpu/drm/i915/i915_drv.c | 5 +++++ > > 3 files changed, 25 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c > > index 833d0c1be4f1..c7b57c22dce3 100644 > > --- a/drivers/gpu/drm/i915/display/intel_acpi.c > > +++ b/drivers/gpu/drm/i915/display/intel_acpi.c > > @@ -14,11 +14,16 @@ > > > > #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */ > > #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */ > > +#define INTEL_DSM_FN_PLATFORM_BXT_MUX_INFO 0 /* No args */ > > > > static const guid_t intel_dsm_guid = > > GUID_INIT(0x7ed873d3, 0xc2d0, 0x4e4f, > > 0xa8, 0x54, 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c); > > > > +static const guid_t intel_bxt_dsm_guid = > > + GUID_INIT(0x3e5b41c6, 0xeb1d, 0x4260, > > + 0x9d, 0x15, 0xc7, 0x1f, 0xba, 0xda, 0xe4, 0x14); > > + > > I think this dsm is just supposed to be more or less an > alternative to the opregion SCI stuff. Why there are two > ways to do the same things I have no idea. The opregion > spec does not tell us such mundane details. Right now I think it's HP specific and from what I can see it doesn't touch opregion. > > It's also not documented to do anything except list the > supported functions: > "Get BIOS Data Functions Supported “Function #0" > This function can be called to discover which “_DSM” Functions are > supported. It may only return success if the return value accurately > lists supported Functions." > > But what you're apparently saying is that calling this changes > the behaviour of the system somehow? That is troubling. It flips a bit in BIOS-reserved Intel GPIO, and EC/hardware will change the MUX based on the GPIO bit. We can add a DMI check to match "HP" to minimize the potential regression factor. Kai-Heng > > -- > Ville Syrjälä > Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
