AW: [PATCH] drm/amdgpu/display: Fix an error handling path in 'dm_update_crtc_state()'

[Walter Harms]

________________________________________
Von: kernel-janitors-owner@xxxxxxxxxxxxxxx <kernel-janitors-owner@xxxxxxxxxxxxxxx> im Auftrag von Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Gesendet: Sonntag, 8. März 2020 10:26
An: harry.wentland@xxxxxxx; sunpeng.li@xxxxxxx; alexander.deucher@xxxxxxx; christian.koenig@xxxxxxx; David1.Zhou@xxxxxxx; airlied@xxxxxxxx; daniel@xxxxxxxx; nicholas.kazlauskas@xxxxxxx; Bhawanpreet.Lakha@xxxxxxx; mario.kleiner.de@xxxxxxxxx; David.Francis@xxxxxxx
Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; kernel-janitors@xxxxxxxxxxxxxxx; Christophe JAILLET
Betreff: [PATCH] drm/amdgpu/display: Fix an error handling path in 'dm_update_crtc_state()'

'dc_stream_release()' may be called twice. Once here, and once below in the
error handling path if we branch to the 'fail' label.

Set 'new_stream' to NULL, once released to avoid the duplicated release
function call.

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Maybe the 'goto fail' at line 7745 should be turned into a 'return ret'
instead. Could be clearer.

No Fixes tag provided because I've not been able to dig deep enough in the
git history.
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

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 97c1b01c0fc1..9d7773a77c4f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7704,8 +7704,10 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,

 skip_modeset:
        /* Release extra reference */
-       if (new_stream)
-                dc_stream_release(new_stream);
+       if (new_stream) {
+               dc_stream_release(new_stream);
+               new_stream = NULL;
+       }


dc_stream_release() is NULL-checked, so the if can be dropped.

re,
 wh

        /*
         * We want to do dc stream updates that do not require a
--
2.20.1