3.16.54-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
commit e30a154b5262b967b133b06ac40777e651045898 upstream.
intel_crtc->config->cpu_transcoder isn't yet filled out when
intel_crtc_mode_get() gets called during output probing, so we should
not use it there. Instead intel_crtc_mode_get() figures out the correct
transcoder on its own, and that's what we should use.
If the BIOS boots LVDS on pipe B, intel_crtc_mode_get() would actually
end up reading the timings from pipe A instead (since PIPE_A==0),
which clearly isn't what we want.
It looks to me like this may have been broken by
commit eccb140bca67 ("drm/i915: hw state readout&check support for cpu_transcoder")
as that one removed the early initialization of cpu_transcoder from
intel_crtc_init().
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: Rob Kramer <rob@xxxxxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Reported-by: Rob Kramer <rob@xxxxxxxxxxxxxxxxxx>
Fixes: eccb140bca67 ("drm/i915: hw state readout&check support for cpu_transcoder")
References: https://lists.freedesktop.org/archives/dri-devel/2016-April/104142.html
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/1459525046-19425-1-git-send-email-ville.syrjala@xxxxxxxxxxxxxxx
[bwh: Backported to 3.16: pipe_config is a struct not a pointer]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_display.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8662,13 +8662,10 @@ struct drm_display_mode *intel_crtc_mode
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
- enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;
+ enum transcoder cpu_transcoder;
struct drm_display_mode *mode;
struct intel_crtc_config pipe_config;
- int htot = I915_READ(HTOTAL(cpu_transcoder));
- int hsync = I915_READ(HSYNC(cpu_transcoder));
- int vtot = I915_READ(VTOTAL(cpu_transcoder));
- int vsync = I915_READ(VSYNC(cpu_transcoder));
+ u32 htot, hsync, vtot, vsync;
enum pipe pipe = intel_crtc->pipe;
mode = kzalloc(sizeof(*mode), GFP_KERNEL);
@@ -8690,6 +8687,13 @@ struct drm_display_mode *intel_crtc_mode
i9xx_crtc_clock_get(intel_crtc, &pipe_config);
mode->clock = pipe_config.port_clock / pipe_config.pixel_multiplier;
+
+ cpu_transcoder = pipe_config.cpu_transcoder;
+ htot = I915_READ(HTOTAL(cpu_transcoder));
+ hsync = I915_READ(HSYNC(cpu_transcoder));
+ vtot = I915_READ(VTOTAL(cpu_transcoder));
+ vsync = I915_READ(VSYNC(cpu_transcoder));
+
mode->hdisplay = (htot & 0xffff) + 1;
mode->htotal = ((htot & 0xffff0000) >> 16) + 1;
mode->hsync_start = (hsync & 0xffff) + 1;