Re: [PATCH 2/2] drm/amdgpu: cleanup debugfs for amdgpu rings

["Das, Nirmoy" <nirmoy.das@xxxxxxx>]

Hi Shashank,

On 9/3/2021 5:51 PM, Das, Nirmoy wrote:
> On 9/3/2021 5:26 PM, Sharma, Shashank wrote:
> > On 9/3/2021 1:39 PM, Das, Nirmoy wrote:
> > > On 9/3/2021 8:36 AM, Sharma, Shashank wrote:
> > > > On 9/2/2021 5:14 PM, Nirmoy Das wrote:
> > > > > Use debugfs_create_file_size API for creating ring debugfs
> > > > > file, also cleanup surrounding code.
> > > > >
> > > > > Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxx>
> > > > > ---
> > > > >   drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c |  4 +---
> > > > >   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c    | 16 +++++-----------
> > > > >   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h    |  8 +-------
> > > > >   3 files changed, 7 insertions(+), 21 deletions(-)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c 
> > > > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> > > > > index 077f9baf74fe..dee56ab19a8f 100644
> > > > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> > > > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> > > > > @@ -1734,9 +1734,7 @@ int amdgpu_debugfs_init(struct amdgpu_device 
> > > > > *adev)
> > > > >           if (!ring)
> > > > >               continue;
> > > > >   -        if (amdgpu_debugfs_ring_init(adev, ring)) {
> > > > > -            DRM_ERROR("Failed to register debugfs file for rings 
> > > > > !\n");
> > > > > -        }
> > > > > +        amdgpu_debugfs_ring_init(adev, ring);
> > > > >       }
> > > > >         amdgpu_ras_debugfs_create_all(adev);
> > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c 
> > > > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> > > > > index f40753e1a60d..968521d80514 100644
> > > > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> > > > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> > > > > @@ -415,26 +415,20 @@ static const struct file_operations 
> > > > > amdgpu_debugfs_ring_fops = {
> > > > >     #endif
> > > > >   -int amdgpu_debugfs_ring_init(struct amdgpu_device *adev,
> > > > > +void amdgpu_debugfs_ring_init(struct amdgpu_device *adev,
> > > > >                    struct amdgpu_ring *ring)
> > > > >   {
> > > > >   #if defined(CONFIG_DEBUG_FS)
> > > > >       struct drm_minor *minor = adev_to_drm(adev)->primary;
> > > > > -    struct dentry *ent, *root = minor->debugfs_root;
> > > > > +    struct dentry *root = minor->debugfs_root;
> > > > >       char name[32];
> > > > >         sprintf(name, "amdgpu_ring_%s", ring->name);
> > > > >   -    ent = debugfs_create_file(name,
> > > > > -                  S_IFREG | S_IRUGO, root,
> > > > > -                  ring, &amdgpu_debugfs_ring_fops);
> > > > > -    if (IS_ERR(ent))
> > > > > -        return -ENOMEM;
> > > >
> > > > Why are we doing this ? Why to make it void from int ?
> > >
> > >
> > > We tend to ignore debugfs return values as those are not serious 
> > > errors. This to sync with rest of our
> > >
> > > debugfs calls.
> > >
> > >
> > > Regards,
> > >
> > > Nirmoy
> >
> >
> > I am not suere if completely removing the provision of return value 
> > is a good way of doing it, we can always ignore it at the caller 
> > side, isn't it ?



I just realized while making the change debugfs_create_file_size() is 
void return, so we don't have anything useful to return in 
amdgpu_debugfs_ring_init()


Regards,

Nirmoy


> Yes, we are currently throwing an error msg and ignoring it. I don't 
> have a strong opinion regarding this, I will send a v2 restoring  
> previous behavior.
>
>
> Thanks,
>
> Nirmoy
>
>
> > - Shashank
> >
> > > > - Shashank
> > > >
> > > >
> > > > > -
> > > > > -    i_size_write(ent->d_inode, ring->ring_size + 12);
> > > > > -    ring->ent = ent;
> > > > > +    debugfs_create_file_size(name, S_IFREG | S_IRUGO, root, ring,
> > > > > +                 &amdgpu_debugfs_ring_fops,
> > > > > +                 ring->ring_size + 12);
> > > > >   #endif
> > > > > -    return 0;
> > > > >   }
> > > > >     /**
> > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h 
> > > > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> > > > > index 88d80eb3fea1..c29fbce0a5b4 100644
> > > > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> > > > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> > > > > @@ -253,10 +253,6 @@ struct amdgpu_ring {
> > > > >       bool            has_compute_vm_bug;
> > > > >       bool            no_scheduler;
> > > > >       int            hw_prio;
> > > > > -
> > > > > -#if defined(CONFIG_DEBUG_FS)
> > > > > -    struct dentry *ent;
> > > > > -#endif
> > > > >   };
> > > > >     #define amdgpu_ring_parse_cs(r, p, ib) 
> > > > > ((r)->funcs->parse_cs((p), (ib)))
> > > > > @@ -356,8 +352,6 @@ static inline void 
> > > > > amdgpu_ring_write_multiple(struct amdgpu_ring *ring,
> > > > >     int amdgpu_ring_test_helper(struct amdgpu_ring *ring);
> > > > >   -int amdgpu_debugfs_ring_init(struct amdgpu_device *adev,
> > > > > +void amdgpu_debugfs_ring_init(struct amdgpu_device *adev,
> > > > >                    struct amdgpu_ring *ring);
> > > > > -void amdgpu_debugfs_ring_fini(struct amdgpu_ring *ring);
> > > > > -
> > > > >   #endif