2024-04-08 08:13:58

by Dan Carpenter

Subject: [PATCH] drm/panthor: clean up some types in panthor_sched_suspend()

These variables should be u32 instead of u64 because they're only
storing u32 values. Also static checkers complain when we do:

suspended_slots &= ~upd_ctx.timedout_mask;

In this code "suspended_slots" is a u64 and "upd_ctx.timedout_mask". The
mask clears out the top 32 bits which would likely be a bug if anything
were stored there.

Signed-off-by: Dan Carpenter <[email protected]>
---
drivers/gpu/drm/panthor/panthor_sched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index d4bc652b34d5..b3a51a6de523 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -2546,7 +2546,7 @@ void panthor_sched_suspend(struct panthor_device *ptdev)
{
struct panthor_scheduler *sched = ptdev->scheduler;
struct panthor_csg_slots_upd_ctx upd_ctx;
- u64 suspended_slots, faulty_slots;
+ u32 suspended_slots, faulty_slots;
struct panthor_group *group;
u32 i;

--
2.43.0

2024-04-08 12:27:30

by Steven Price

Subject: Re: [PATCH] drm/panthor: clean up some types in panthor_sched_suspend()

On 08/04/2024 08:36, Dan Carpenter wrote:
> These variables should be u32 instead of u64 because they're only
> storing u32 values. Also static checkers complain when we do:
>
> suspended_slots &= ~upd_ctx.timedout_mask;
>
> In this code "suspended_slots" is a u64 and "upd_ctx.timedout_mask". The
> mask clears out the top 32 bits which would likely be a bug if anything
> were stored there.
>
> Signed-off-by: Dan Carpenter <[email protected]>

Reviewed-by: Steven Price <[email protected]>

If you fancy a bit more clean-up then I think faulty_slots is completely
redundant as a separate variable. In particular in the "if
(suspended_slots)" section it's updated but that updated value is never
used... otherwise I'll put it on my list for cleaning up later.

> ---
> drivers/gpu/drm/panthor/panthor_sched.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> index d4bc652b34d5..b3a51a6de523 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -2546,7 +2546,7 @@ void panthor_sched_suspend(struct panthor_device *ptdev)
> {
> struct panthor_scheduler *sched = ptdev->scheduler;
> struct panthor_csg_slots_upd_ctx upd_ctx;
> - u64 suspended_slots, faulty_slots;
> + u32 suspended_slots, faulty_slots;
> struct panthor_group *group;
> u32 i;
>

2024-04-17 09:30:31

by Boris Brezillon

Subject: Re: [PATCH] drm/panthor: clean up some types in panthor_sched_suspend()

On Mon, 8 Apr 2024 13:27:17 +0100
Steven Price <[email protected]> wrote:

> On 08/04/2024 08:36, Dan Carpenter wrote:
> > These variables should be u32 instead of u64 because they're only
> > storing u32 values. Also static checkers complain when we do:
> >
> > suspended_slots &= ~upd_ctx.timedout_mask;
> >
> > In this code "suspended_slots" is a u64 and "upd_ctx.timedout_mask". The

'and "upd_ctx.timedout_mask" an u32.'?

> > mask clears out the top 32 bits which would likely be a bug if anything
> > were stored there.
> >
> > Signed-off-by: Dan Carpenter <[email protected]>
>
> Reviewed-by: Steven Price <[email protected]>

Reviewed-by: Boris Brezillon <[email protected]>

>
> If you fancy a bit more clean-up then I think faulty_slots is completely
> redundant as a separate variable. In particular in the "if
> (suspended_slots)" section it's updated but that updated value is never
> used... otherwise I'll put it on my list for cleaning up later.

Yeah, I think this variable predates the upd_ctx stuff and is now useless.
I you post such a patch, please add my R-b directly.

Thanks,

Boris

>
> > ---
> > drivers/gpu/drm/panthor/panthor_sched.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> > index d4bc652b34d5..b3a51a6de523 100644
> > --- a/drivers/gpu/drm/panthor/panthor_sched.c
> > +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> > @@ -2546,7 +2546,7 @@ void panthor_sched_suspend(struct panthor_device *ptdev)
> > {
> > struct panthor_scheduler *sched = ptdev->scheduler;
> > struct panthor_csg_slots_upd_ctx upd_ctx;
> > - u64 suspended_slots, faulty_slots;
> > + u32 suspended_slots, faulty_slots;
> > struct panthor_group *group;
> > u32 i;
> >
>