Nouveau - Jul 2022 - [PATCH] drm/nouveau/bios: set info only when the return is not 0

Reviewed-by: Lyude Paul <lyude at redhat.com>

Currently on flakey internet in the back of a car, so I probably won't be
able
to push this until I get back tonight or early tomorrow

On Sat, 2022-07-02 at 11:39 -0400, Tom Rix wrote:
> clang static analysis reports
> drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c:68:17: warning: The right
> operand of '*' is a garbage value
[core.UndefinedBinaryOperatorResult]
> ??????? switch (!!data * *ver) {
> ?????????????????????? ^ ~~~~
> A switch statement with only a default should be reduced to an if.
> 
> If nvbios_pmuEp() returns 0, via the data variable, the output info
> parameter
> is not used.? So set info only when data is not 0.
> 
> The struct nvbios_pmuE only has the type and data elements.? Since both of
> these
> are explicitly set, memset is not needed.? So remove it.
> 
> Signed-off-by: Tom Rix <trix at redhat.com>
> ---
> ?drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c | 5 +----
> ?1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> index b4a308f3cf7b..49e2664a734c 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> @@ -64,12 +64,9 @@ nvbios_pmuEp(struct nvkm_bios *bios, int idx, u8 *ver,
u8
> *hdr,
> ???????????? struct nvbios_pmuE *info)
> ?{
> ????????u32 data = nvbios_pmuEe(bios, idx, ver, hdr);
> -???????memset(info, 0x00, sizeof(*info));
> -???????switch (!!data * *ver) {
> -???????default:
> +???????if (data) {
> ????????????????info->type = nvbios_rd08(bios, data + 0x00);
> ????????????????info->data = nvbios_rd32(bios, data + 0x02);
> -???????????????break;
> ????????}
> ????????return data;
> ?}
-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat

On Mon, 2022-07-04 at 17:32 -0400, Lyude Paul wrote:
> Reviewed-by: Lyude Paul <lyude at redhat.com>
> 
> Currently on flakey internet in the back of a car, so I probably won't
be
> able
> to push this until I get back tonight or early tomorrow
Whoops! Slipped my mind when I got back, but I just remembered it now so I
will go ahead and push :). apologies for the delay!
> 
> On Sat, 2022-07-02 at 11:39 -0400, Tom Rix wrote:
> > clang static analysis reports
> > drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c:68:17: warning: The
right
> > operand of '*' is a garbage value
[core.UndefinedBinaryOperatorResult]
> > ??????? switch (!!data * *ver) {
> > ?????????????????????? ^ ~~~~
> > A switch statement with only a default should be reduced to an if.
> > 
> > If nvbios_pmuEp() returns 0, via the data variable, the output info
> > parameter
> > is not used.? So set info only when data is not 0.
> > 
> > The struct nvbios_pmuE only has the type and data elements.? Since
both of
> > these
> > are explicitly set, memset is not needed.? So remove it.
> > 
> > Signed-off-by: Tom Rix <trix at redhat.com>
> > ---
> > ?drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c | 5 +----
> > ?1 file changed, 1 insertion(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> > b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> > index b4a308f3cf7b..49e2664a734c 100644
> > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/pmu.c
> > @@ -64,12 +64,9 @@ nvbios_pmuEp(struct nvkm_bios *bios, int idx, u8
*ver,
> > u8
> > *hdr,
> > ???????????? struct nvbios_pmuE *info)
> > ?{
> > ????????u32 data = nvbios_pmuEe(bios, idx, ver, hdr);
> > -???????memset(info, 0x00, sizeof(*info));
> > -???????switch (!!data * *ver) {
> > -???????default:
> > +???????if (data) {
> > ????????????????info->type = nvbios_rd08(bios, data + 0x00);
> > ????????????????info->data = nvbios_rd32(bios, data + 0x02);
> > -???????????????break;
> > ????????}
> > ????????return data;
> > ?}
> 
-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat