From: Harry Wentland <harry.wentland@xxxxxxx> commit c6c6a712199ab355ce333fa5764a59506bb107c1 upstream. [Why] This hasn't been well tested and leads to complete system hangs on DCN1 based systems, possibly others. The system hang can be reproduced by gesturing the video on the YouTube Android app on ChromeOS into full screen. [How] Reject atomic commits with non-zero drm_plane_state.src_x or src_y values. v2: - Add code comment describing the reason we're rejecting non-zero src_x and src_y - Drop gerrit Change-Id - Add stable CC - Based on amd-staging-drm-next v3: removed trailing whitespace Signed-off-by: Harry Wentland <harry.wentland@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Cc: nicholas.kazlauskas@xxxxxxx Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx Cc: alexander.deucher@xxxxxxx Cc: Roman.Li@xxxxxxx Cc: hersenxs.wu@xxxxxxx Cc: danny.wang@xxxxxxx Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> Acked-by: Christian König <christian.koenig@xxxxxxx> Reviewed-by: Hersen Wu <hersenxs.wu@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -3702,6 +3702,23 @@ static int fill_dc_scaling_info(const st scaling_info->src_rect.y != 0)) return -EINVAL; + /* + * For reasons we don't (yet) fully understand a non-zero + * src_y coordinate into an NV12 buffer can cause a + * system hang. To avoid hangs (and maybe be overly cautious) + * let's reject both non-zero src_x and src_y. + * + * We currently know of only one use-case to reproduce a + * scenario with non-zero src_x and src_y for NV12, which + * is to gesture the YouTube Android app into full screen + * on ChromeOS. + */ + if (state->fb && + state->fb->format->format == DRM_FORMAT_NV12 && + (scaling_info->src_rect.x != 0 || + scaling_info->src_rect.y != 0)) + return -EINVAL; + scaling_info->src_rect.width = state->src_w >> 16; if (scaling_info->src_rect.width == 0) return -EINVAL;
