Re: [PATCH v2] drm/amd/amdgpu: Fix an uninitialized variable

[Christian König <christian.koenig@xxxxxxx>]

Am 09.01.23 um 17:19 schrieb Limonciello, Mario:
> [Public]
>
>
>
> > -----Original Message-----
> > From: Alex Deucher <alexdeucher@xxxxxxxxx>
> > Sent: Monday, January 9, 2023 10:04
> > To: SHANMUGAM, SRINIVASAN <SRINIVASAN.SHANMUGAM@xxxxxxx>
> > Cc: Wentland, Harry <Harry.Wentland@xxxxxxx>; Deucher, Alexander
> > <Alexander.Deucher@xxxxxxx>; Koenig, Christian
> > <Christian.Koenig@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Limonciello,
> > Mario <Mario.Limonciello@xxxxxxx>
> > Subject: Re: [PATCH v2] drm/amd/amdgpu: Fix an uninitialized variable
> >
> > On Mon, Jan 9, 2023 at 10:58 AM Srinivasan Shanmugam
> > <srinivasan.shanmugam@xxxxxxx> wrote:
> > >    CC      drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.o
> > > drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c:217:71: error: variable 'i' is
> > uninitialized when used here [-Werror,-Wuninitialized]
> > >                  snprintf(fw_name, sizeof(fw_name), "amdgpu/%s%d.bin",
> > ucode_prefix, i);
> > >                                                                                      ^
> > > drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c:207:16: note: initialize the
> > variable 'i' to silence this warning
> > >          int err = 0, i;
> > >                        ^
> > >                         = 0
> > >
> > > As suggested by Christian, buggy
> > > "snprintf(fw_name, sizeof(fw_name), "amdgpu/%s%d.bin", ucode_prefix,
> > i);"
> > > shouldn't be "i" in the first place, but rather using "instance",
> > > because for instance greater than 0, we want to have different
> > > sdma firmware for different instance we add the instance number.
> > >
> > > Remove setting err to 0 as well. This is considered very bad coding style.
> > >
> > > Cc: Christian König <christian.koenig@xxxxxxx>
> > > Cc: Mario Limonciello <mario.limonciello@xxxxxxx>
> > > Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> > > Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
> > Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
> Thanks for the fix!
>
> Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>

Reviewed-by: Christian König <christian.koenig@xxxxxxx>

> > > Change-Id: I2f1180af4f37bf1efd4d47e7bf64425b0b3809fb
> > > ---
> > >   drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 4 ++--
> > >   1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> > > index 0e1e2521fe25a..e9b78739b9ff7 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> > > @@ -204,7 +204,7 @@ int amdgpu_sdma_init_microcode(struct
> > amdgpu_device *adev,
> > >   {
> > >          struct amdgpu_firmware_info *info = NULL;
> > >          const struct common_firmware_header *header = NULL;
> > > -       int err = 0, i;
> > > +       int err, i;
> > >          const struct sdma_firmware_header_v2_0 *sdma_hdr;
> > >          uint16_t version_major;
> > >          char ucode_prefix[30];
> > > @@ -214,7 +214,7 @@ int amdgpu_sdma_init_microcode(struct
> > amdgpu_device *adev,
> > >          if (instance == 0)
> > >                  snprintf(fw_name, sizeof(fw_name), "amdgpu/%s.bin",
> > ucode_prefix);
> > >          else
> > > -               snprintf(fw_name, sizeof(fw_name), "amdgpu/%s%d.bin",
> > ucode_prefix, i);
> > > +               snprintf(fw_name, sizeof(fw_name), "amdgpu/%s%d.bin",
> > ucode_prefix, instance);
> > >          err = amdgpu_ucode_request(adev, &adev-
> > > sdma.instance[instance].fw, fw_name);
> > >          if (err)
> > >                  goto out;
> > > --
> > > 2.25.1