diff options
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_vga.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index 84fd5475d336..744812260ae3 100644 --- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -23,6 +23,18 @@ static unsigned int intel_gmch_ctrl_reg(struct intel_display *display) return DISPLAY_VER(display) >= 6 ? SNB_GMCH_CTRL : INTEL_GMCH_CTRL; } +static bool intel_vga_decode_is_enabled(struct intel_display *display) +{ + struct pci_dev *pdev = to_pci_dev(display->drm->dev); + u16 gmch_ctrl = 0; + + if (pci_bus_read_config_word(pdev->bus, PCI_DEVFN(0, 0), + intel_gmch_ctrl_reg(display), &gmch_ctrl)) + return false; + + return !(gmch_ctrl & INTEL_GMCH_VGA_DISABLE); +} + static i915_reg_t intel_vga_cntrl_reg(struct intel_display *display) { if (display->platform.valleyview || display->platform.cherryview) @@ -55,6 +67,17 @@ void intel_vga_disable(struct intel_display *display) u8 msr, sr1; u32 tmp; + if (!intel_vga_decode_is_enabled(display)) { + drm_dbg_kms(display->drm, "VGA decode is disabled\n"); + + /* + * On older hardware VGA_DISP_DISABLE defaults to 0, but + * it *must* be set or else the pipe will be completely + * stuck (at least on g4x). + */ + goto reset_vgacntr; + } + tmp = intel_de_read(display, vga_reg); if (tmp & VGA_DISP_DISABLE) return; @@ -96,6 +119,7 @@ void intel_vga_disable(struct intel_display *display) udelay(300); +reset_vgacntr: intel_de_write(display, vga_reg, VGA_DISP_DISABLE); intel_de_posting_read(display, vga_reg); } |