From c6016936171a7b179b2c478ceb7fbd092ee4f9f8 Mon Sep 17 00:00:00 2001 From: Harry Wentland Date: Thu, 22 Apr 2021 19:10:52 -0400 Subject: [PATCH] drm/amd/display: Reject non-zero src_y and src_x for video planes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Cc: stable@vger.kernel.org Cc: nicholas.kazlauskas@amd.com Cc: amd-gfx@lists.freedesktop.org Cc: alexander.deucher@amd.com Cc: Roman.Li@amd.com Cc: hersenxs.wu@amd.com Cc: danny.wang@amd.com Reviewed-by: Nicholas Kazlauskas Acked-by: Christian König Reviewed-by: Hersen Wu Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index bdcec5b..6eb3086 100644 --- 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 struct drm_plane_state *state, 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; -- 2.7.4