If all pipes are off, then we may have entered runtime suspend and writing these registers will have no effect anyway. When a pipe is re-enabled, it's crtc_enable will take care of programming appropriate watermark values. Cc: arun.siluvery@xxxxxxxxxxxxxxx Cc: ville.syrjala@xxxxxxxxxxxxxxx Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94349 Fixes: ed4a6a7ca853 ("drm/i915: Add two-stage ILK-style watermark programming (v11)") Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx> --- I've still been unable to reproduce this defect on my SNB system; none of the suggested tests people have noted in Bugzilla have triggered it for me. But based on the stack trace I'm guessing that the problem happens because we've disabled the last pipe and gone into runtime suspend before we get around to optimizing the watermarks. I'm not super familiar with the details of runtime PM, so if there's a better way this should be handled, I'm open to suggestions. drivers/gpu/drm/i915/intel_pm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index f65e841..8c7fddf 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2802,8 +2802,6 @@ static void ilk_write_wm_values(struct drm_i915_private *dev_priv, I915_WRITE(WM2_LP_ILK, results->wm_lp[1]); if (dirty & WM_DIRTY_LP(3) && previous->wm_lp[2] != results->wm_lp[2]) I915_WRITE(WM3_LP_ILK, results->wm_lp[2]); - - dev_priv->wm.hw = *results; } bool ilk_disable_lp_wm(struct drm_device *dev) @@ -3731,7 +3729,10 @@ static void ilk_program_watermarks(struct drm_i915_private *dev_priv) ilk_compute_wm_results(dev, best_lp_wm, partitioning, &results); - ilk_write_wm_values(dev_priv, &results); + if (config.num_pipes_active > 0) + ilk_write_wm_values(dev_priv, &results); + + dev_priv->wm.hw = results; } static void ilk_initial_watermarks(struct intel_crtc_state *cstate) -- 2.1.4 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
