diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2025-12-08 20:26:31 +0200 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2026-01-23 05:20:28 +0200 |
| commit | 359dd735ef833f2d9b75917794d049761f9e007c (patch) | |
| tree | 8bf41a81c595636848264f13e4a28d02fb4978f2 | |
| parent | 3acd8cbbd738eb8c85fc5ec3c7d9fbee26db6d04 (diff) | |
drm/i915/vga: Use MMIO for VGA registers on pre-g4x
On pre-g4x VGA registers are accessible via MMIO. Make use of
it so that we can avoid dealing with the VGA arbiter.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251208182637.334-14-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_vga.c | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index c1942520c765..9e1f3ab632d5 100644 --- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -58,6 +58,12 @@ static bool has_vga_pipe_sel(struct intel_display *display) return DISPLAY_VER(display) < 7; } +static bool has_vga_mmio_access(struct intel_display *display) +{ + /* WaEnableVGAAccessThroughIOPort:ctg+ */ + return DISPLAY_VER(display) < 5 && !display->platform.g4x; +} + static bool intel_pci_has_vga_io_decode(struct pci_dev *pdev) { u16 cmd = 0; @@ -106,11 +112,12 @@ static bool intel_pci_bridge_set_vga(struct pci_dev *pdev, bool enable) return old & PCI_BRIDGE_CTL_VGA; } -static bool intel_vga_get(struct intel_display *display) +static bool intel_vga_get(struct intel_display *display, bool mmio) { struct pci_dev *pdev = to_pci_dev(display->drm->dev); - /* WaEnableVGAAccessThroughIOPort:ctg+ */ + if (mmio) + return false; /* * Bypass the VGA arbiter on the iGPU and just enable @@ -129,10 +136,13 @@ static bool intel_vga_get(struct intel_display *display) return intel_pci_set_io_decode(pdev, true); } -static void intel_vga_put(struct intel_display *display, bool io_decode) +static void intel_vga_put(struct intel_display *display, bool io_decode, bool mmio) { struct pci_dev *pdev = to_pci_dev(display->drm->dev); + if (mmio) + return; + /* see intel_vga_get() */ intel_pci_set_io_decode(pdev, io_decode); @@ -161,6 +171,7 @@ void intel_vga_disable(struct intel_display *display) { struct pci_dev *pdev = to_pci_dev(display->drm->dev); i915_reg_t vga_reg = intel_vga_cntrl_reg(display); + bool mmio = has_vga_mmio_access(display); bool io_decode; u8 msr, sr1; u32 tmp; @@ -205,16 +216,16 @@ void intel_vga_disable(struct intel_display *display) goto reset_vgacntr; } - io_decode = intel_vga_get(display); + io_decode = intel_vga_get(display, mmio); - drm_WARN_ON(display->drm, !intel_pci_has_vga_io_decode(pdev)); + drm_WARN_ON(display->drm, !mmio && !intel_pci_has_vga_io_decode(pdev)); - intel_vga_write(display, VGA_SEQ_I, 0x01, false); - sr1 = intel_vga_read(display, VGA_SEQ_D, false); + intel_vga_write(display, VGA_SEQ_I, 0x01, mmio); + sr1 = intel_vga_read(display, VGA_SEQ_D, mmio); sr1 |= VGA_SR01_SCREEN_OFF; - intel_vga_write(display, VGA_SEQ_D, sr1, false); + intel_vga_write(display, VGA_SEQ_D, sr1, mmio); - msr = intel_vga_read(display, VGA_MIS_R, false); + msr = intel_vga_read(display, VGA_MIS_R, mmio); /* * Always disable VGA memory decode for iGPU so that * intel_vga_set_decode() doesn't need to access VGA registers. @@ -234,9 +245,9 @@ void intel_vga_disable(struct intel_display *display) * RMbus NoClaim errors. */ msr &= ~VGA_MIS_COLOR; - intel_vga_write(display, VGA_MIS_W, msr, false); + intel_vga_write(display, VGA_MIS_W, msr, mmio); - intel_vga_put(display, io_decode); + intel_vga_put(display, io_decode, mmio); /* * Inform the arbiter about VGA memory decode being disabled so |