This series fixes an intermittent blue screen seen on the Samsung Galaxy S4 with the MDP4 display controller. The issue happens on roughly half of boots.
The first patch keeps the AXI/bus clock enabled while a CRTC is active, so scanout does not lose bus access while the display pipeline is still running. The second patch handles the case where firmware left the display pipeline enabled before Linux takes over. In that case, the required display clocks are kept enabled until the first DRM modeset, where the driver takes ownership of the pipeline. Tested on a Samsung Galaxy S4 GT-I9505, codename jflte. Signed-off-by: Alexandre MINETTE <[email protected]> --- Alexandre MINETTE (2): drm/msm/mdp4: keep the bus clock enabled while a CRTC is active drm/msm/mdp4: keep inherited display clocks enabled until modeset drivers/gpu/drm/msm/disp/mdp4/mdp4_crtc.c | 3 + drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c | 108 +++++++++++++++++++++++++++++- drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h | 8 +++ 3 files changed, 118 insertions(+), 1 deletion(-) --- base-commit: acb7500801e98639f6d8c2d796ed9f64cba83d3a change-id: 20260610-mainline-fix-mdp4-blue-screen-sending-v1-0637d7a6c355 Best regards, -- Alexandre MINETTE <[email protected]>
