4.9-stable review patch. If anyone has any objections, please let me know.

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From: Ville Syrjälä ville.syrjala@linux.intel.com

commit 7b50f7b24cd6c98541f1af53bddc5b6e861ee8c8 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@lists.freedesktop.org Cc: Rob Kramer rob@solution-space.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Reported-by: Rob Kramer rob@solution-space.com 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@linux.intel.com Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Link: https://patchwork.freedesktop.org/patch/msgid/1459525046-19425-1-git-send-em... (cherry picked from commit e30a154b5262b967b133b06ac40777e651045898) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- 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 @@ -11471,13 +11471,10 @@ struct drm_display_mode *intel_crtc_mode { struct drm_i915_private *dev_priv = to_i915(dev); 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_state *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); @@ -11505,6 +11502,13 @@ 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;