drm/i915: Handle PipeC fused off on IVB/HSW/BDW
Some Gen7/8 production parts may have the Display Pipe C fused off.
In this case, the display hardware will prevent the enable bit in
PIPE_CONF register (for Pipe C) from being set to 1.
Fixed by adjusting pipe_count to reflect this.
v2: Rename HSW_PIPE_C_DISABLE to IVB_PIPE_C_DISABLE as it already exists
on ivybridge (Ville)
v3: Remove unnecessary MMIO read, correct the description (Damien)
v4: Be more specific in description (Patrick)
Signed-off-by: Gabriel Feceoru <gabriel.feceoru@intel.com>
Reviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1453462125-21519-1-git-send-email-gabriel.feceoru@intel.com
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index a42eb58..35c2b33 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -808,6 +808,9 @@
!(sfuse_strap & SFUSE_STRAP_FUSE_LOCK))) {
DRM_INFO("Display fused off, disabling\n");
info->num_pipes = 0;
+ } else if (fuse_strap & IVB_PIPE_C_DISABLE) {
+ DRM_INFO("PipeC fused off\n");
+ info->num_pipes -= 1;
}
} else if (info->num_pipes > 0 && INTEL_INFO(dev)->gen == 9) {
u32 dfsm = I915_READ(SKL_DFSM);