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.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3113 References: https://lore.kernel.org/intel-gfx/1460040732-31417-4-git-send-email-animesh.... Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com --- drivers/gpu/drm/i915/display/intel_acpi.c | 17 +++++++++++++++++ drivers/gpu/drm/i915/display/intel_acpi.h | 2 ++ drivers/gpu/drm/i915/i915_drv.c | 5 +++++ 3 files changed, 24 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); + static char *intel_dsm_port_name(u8 id) { switch (id) { @@ -176,6 +181,18 @@ void intel_unregister_dsm_handler(void) { }

+void intel_bxt_dsm_detect(struct pci_dev *pdev) +{ + acpi_handle dhandle; + + dhandle = ACPI_HANDLE(&pdev->dev); + if (!dhandle) + return; + + acpi_evaluate_dsm(dhandle, &intel_bxt_dsm_guid, INTEL_DSM_REVISION_ID, + INTEL_DSM_FN_PLATFORM_BXT_MUX_INFO, NULL); +} + /* * ACPI Specification, Revision 5.0, Appendix B.3.2 _DOD (Enumerate All Devices * Attached to the Display Adapter). diff --git a/drivers/gpu/drm/i915/display/intel_acpi.h b/drivers/gpu/drm/i915/display/intel_acpi.h index e8b068661d22..0dd456335bd0 100644 --- a/drivers/gpu/drm/i915/display/intel_acpi.h +++ b/drivers/gpu/drm/i915/display/intel_acpi.h @@ -11,10 +11,12 @@ struct drm_i915_private; #ifdef CONFIG_ACPI void intel_register_dsm_handler(void); void intel_unregister_dsm_handler(void); +void intel_bxt_dsm_detect(struct pci_dev *pdev); void intel_acpi_device_id_update(struct drm_i915_private *i915); #else static inline void intel_register_dsm_handler(void) { return; } static inline void intel_unregister_dsm_handler(void) { return; } +static inline void intel_bxt_dsm_detect(struct pci_dev *pdev) { return; } static inline void intel_acpi_device_id_update(struct drm_i915_private *i915) { return; } #endif /* CONFIG_ACPI */ diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 785dcf20c77b..57b12068aab4 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -853,6 +853,8 @@ int i915_driver_probe(struct pci_dev *pdev, const struct pci_device_id *ent) if (ret) goto out_cleanup_gem;

+ intel_bxt_dsm_detect(pdev); + i915_driver_register(i915);

enable_rpm_wakeref_asserts(&i915->runtime_pm); @@ -1215,6 +1217,7 @@ int i915_suspend_switcheroo(struct drm_i915_private *i915, pm_message_t state) static int i915_drm_resume(struct drm_device *dev) { struct drm_i915_private *dev_priv = to_i915(dev); + struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev); int ret;

disable_rpm_wakeref_asserts(&dev_priv->runtime_pm); @@ -1271,6 +1274,8 @@ static int i915_drm_resume(struct drm_device *dev)

intel_gvt_resume(dev_priv);

+ intel_bxt_dsm_detect(pdev); + enable_rpm_wakeref_asserts(&dev_priv->runtime_pm);

return 0;