Messages in this thread | | | Date | Mon, 15 Aug 2022 23:01:49 +0600 | Subject | Re: [PATCH linux-next] drm/amdgpu/vcn: Remove unused assignment in vcn_v4_0_stop | From | Khalid Masum <> |
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On 8/15/22 22:12, Greg KH wrote: > On Mon, Aug 15, 2022 at 09:11:18PM +0600, Khalid Masum wrote: >> On 8/15/22 20:15, Dong, Ruijing wrote: >>> [AMD Official Use Only - General] >>> >>> Sorry, which "r" value was overwritten? I didn't see the point of making this change. >>> >>> Thanks >>> Ruijing >>> >>> -----Original Message----- >>> From: Khalid Masum <khalid.masum.92@gmail.com> >>> Sent: Monday, August 15, 2022 3:01 AM >>> To: amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; linux-kernel@vger.kernel.org; linux-kernel-mentees@lists.linuxfoundation.org >>> Cc: Deucher, Alexander <Alexander.Deucher@amd.com>; Koenig, Christian <Christian.Koenig@amd.com>; Pan, Xinhui <Xinhui.Pan@amd.com>; David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; Zhu, James <James.Zhu@amd.com>; Jiang, Sonny <Sonny.Jiang@amd.com>; Dong, Ruijing <Ruijing.Dong@amd.com>; Wan Jiabing <wanjiabing@vivo.com>; Liu, Leo <Leo.Liu@amd.com>; Khalid Masum <khalid.masum.92@gmail.com> >>> Subject: [PATCH linux-next] drm/amdgpu/vcn: Remove unused assignment in vcn_v4_0_stop >>> >>> The value assigned from vcn_v4_0_stop_dbg_mode to r is overwritten before it can be used. Remove this assignment. >>> >>> Addresses-Coverity: 1504988 ("Unused value") >>> Fixes: 8da1170a16e4 ("drm/amdgpu: add VCN4 ip block support") >>> Signed-off-by: Khalid Masum <khalid.masum.92@gmail.com> >>> --- >>> drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c >>> index ca14c3ef742e..80b8a2c66b36 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c >>> @@ -1154,7 +1154,7 @@ static int vcn_v4_0_stop(struct amdgpu_device *adev) >>> fw_shared->sq.queue_mode |= FW_QUEUE_DPG_HOLD_OFF; >>> >>> if (adev->pg_flags & AMD_PG_SUPPORT_VCN_DPG) { >>> - r = vcn_v4_0_stop_dpg_mode(adev, i); >>> + vcn_v4_0_stop_dpg_mode(adev, i); >>> continue; >>> } >>> >>> -- >>> 2.37.1 >>> >> >> After value is overwritten soon right after the diff. >> >> See: >> drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c >> >> static int vcn_v4_0_stop(struct amdgpu_device *adev) >> { >> volatile struct amdgpu_vcn4_fw_shared *fw_shared; >> ... >> >> for (i = 0; i < adev->vcn.num_vcn_inst; ++i) { >> fw_shared = adev->vcn.inst[i].fw_shared.cpu_addr; >> fw_shared->sq.queue_mode |= FW_QUEUE_DPG_HOLD_OFF; >> >> if (adev->pg_flags & AMD_PG_SUPPORT_VCN_DPG) { >> r = vcn_v4_0_stop_dpg_mode(adev, i); >> continue; >> } >> >> /* wait for vcn idle */ >> r = SOC15_WAIT_ON_RREG(VCN, i, regUVD_STATUS, >> UVD_STATUS__IDLE, 0x7); >> >> Here, any value assigned to r is overwritten before it could >> be used. So the assignment in the true branch of the if statement >> here can be removed. > > Why not fix vcn_v4_0_stop_dpg_mode() to not return anything, as it does > not, and then remove this assignment as well, which would fix up > everything at once to be more obvious what is happening and why.
That makes sense. I shall send a v2 this way. Thanks for your suggestion.
> > thanks, > > greg k-h
thanks, -- Khalid Masum
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