| Message ID | 20230310184233.284388-1-hamza.mahfooz@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/amd/display: use a more accurate check in dm_helpers_dp_read_dpcd() | expand |
On 3/10/23 13:42, Hamza Mahfooz wrote: > We should be checking if drm_dp_dpcd_read() returns the size that we are > asking it to read instead of just checking if it is greater than zero. > So, compare the return value of drm_dp_dpcd_read() to the requested > read size. > > Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com> I don't think we can ever hit a case where the return value is greater than 0 but not equal to size as drm_dp_dpcd_access already checks for it. Either way, the stricter check makes sense and is Reviewed-by: Harry Wentland <harry.wentland@amd.com> Harry > --- > v2: drop the WARN_ON(). > --- > drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c > index 8d598b322e5b..9c1e91c2179e 100644 > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c > @@ -511,8 +511,8 @@ bool dm_helpers_dp_read_dpcd( > return false; > } > > - return drm_dp_dpcd_read(&aconnector->dm_dp_aux.aux, address, > - data, size) > 0; > + return drm_dp_dpcd_read(&aconnector->dm_dp_aux.aux, address, data, > + size) == size; > } > > bool dm_helpers_dp_write_dpcd(
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index 8d598b322e5b..9c1e91c2179e 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -511,8 +511,8 @@ bool dm_helpers_dp_read_dpcd( return false; } - return drm_dp_dpcd_read(&aconnector->dm_dp_aux.aux, address, - data, size) > 0; + return drm_dp_dpcd_read(&aconnector->dm_dp_aux.aux, address, data, + size) == size; } bool dm_helpers_dp_write_dpcd(
We should be checking if drm_dp_dpcd_read() returns the size that we are asking it to read instead of just checking if it is greater than zero. So, compare the return value of drm_dp_dpcd_read() to the requested read size. Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com> --- v2: drop the WARN_ON(). --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)