Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.11 12/13] drm/i915: Always recompute watermarks when distrust_bios_wm is set, v2. | Date | Thu, 15 Jun 2017 19:54:46 +0200 |
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4.11-stable review patch. If anyone has any objections, please let me know.
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From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
commit 4e3aed844547f63614363a386de126e6304e55fb upstream.
On some systems there can be a race condition in which no crtc state is added to the first atomic commit. This results in all crtc's having a null DDB allocation, causing a FIFO underrun on any update until the first modeset.
Changes since v1: - Do not take the connection_mutex, this is already done below.
Reported-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Inspired-by: Mahesh Kumar <mahesh1.kumar@intel.com> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Fixes: 98d39494d375 ("drm/i915/gen9: Compute DDB allocation at atomic check time (v4)") Cc: Mahesh Kumar <mahesh1.kumar@intel.com> Cc: Matt Roper <matthew.d.roper@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170531154236.27180-1-maarten.lankhorst@linux.intel.com Reviewed-by: Mahesh Kumar <mahesh1.kumar@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 367d73d2806085bb507ab44c1f532640917fd5ca) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
--- drivers/gpu/drm/i915/intel_pm.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4140,11 +4140,19 @@ skl_compute_wm(struct drm_atomic_state * struct drm_crtc_state *cstate; struct intel_atomic_state *intel_state = to_intel_atomic_state(state); struct skl_wm_values *results = &intel_state->wm_results; + struct drm_device *dev = state->dev; struct skl_pipe_wm *pipe_wm; bool changed = false; int ret, i; /* + * When we distrust bios wm we always need to recompute to set the + * expected DDB allocations for each CRTC. + */ + if (to_i915(dev)->wm.distrust_bios_wm) + changed = true; + + /* * If this transaction isn't actually touching any CRTC's, don't * bother with watermark calculation. Note that if we pass this * test, we're guaranteed to hold at least one CRTC state mutex, @@ -4154,6 +4162,7 @@ skl_compute_wm(struct drm_atomic_state * */ for_each_crtc_in_state(state, crtc, cstate, i) changed = true; + if (!changed) return 0;
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