[PATCH v2 3/3] drm/msm/dpu: switch dpu_encoder to use drm_debugfs_add_file()

[Dmitry Baryshkov]

On Wed, 24 May 2023 at 02:37, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 5/21/2023 12:22 PM, Dmitry Baryshkov wrote:
> > Use drm_debugfs_add_file() for encoder's status file. This changes the
> > name of the status file from encoder%d/status to just encoder%d.
> >
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
>
> This patch depends on
> https://patchwork.freedesktop.org/patch/538294/?series=118079&rev=1 right?

No, there is no dependency. I have sent that patch as we discussed it
earlier. But this one is a reimplementation of the previous idea.

>
> What is wrong with having a per encoder directory and reading from
> there? It gives room for expanding this to dump more encoder specific
> information.
>
> At the moment it looks light because we have only status but better to
> have a directory per encoder right?

I started writing that I can not imagine additional per-encoder data,
but then I found the generic enough piece: bridge chain enumeration.
I'll give it additional thought and maybe I'll refactor this patch
further.

>
> > ---
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 40 ++++++---------------
> >   1 file changed, 11 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > index af34932729db..0ac68f44ec74 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > @@ -14,6 +14,7 @@
> >
> >   #include <drm/drm_atomic.h>
> >   #include <drm/drm_crtc.h>
> > +#include <drm/drm_debugfs.h>
> >   #include <drm/drm_file.h>
> >   #include <drm/drm_probe_helper.h>
> >
> > @@ -142,7 +143,6 @@ enum dpu_enc_rc_states {
> >    * @crtc_kickoff_cb:                Callback into CRTC that will flush & start
> >    *                          all CTL paths
> >    * @crtc_kickoff_cb_data:   Opaque user data given to crtc_kickoff_cb
> > - * @debugfs_root:            Debug file system root file node
> >    * @enc_lock:                       Lock around physical encoder
> >    *                          create/destroy/enable/disable
> >    * @frame_busy_mask:                Bitmask tracking which phys_enc we are still
> > @@ -186,7 +186,6 @@ struct dpu_encoder_virt {
> >       struct drm_crtc *crtc;
> >       struct drm_connector *connector;
> >
> > -     struct dentry *debugfs_root;
> >       struct mutex enc_lock;
> >       DECLARE_BITMAP(frame_busy_mask, MAX_PHYS_ENCODERS_PER_VIRTUAL);
> >       void (*crtc_frame_event_cb)(void *, u32 event);
> > @@ -2091,7 +2090,8 @@ void dpu_encoder_helper_phys_cleanup(struct dpu_encoder_phys *phys_enc)
> >   #ifdef CONFIG_DEBUG_FS
> >   static int _dpu_encoder_status_show(struct seq_file *s, void *data)
> >   {
> > -     struct dpu_encoder_virt *dpu_enc = s->private;
> > +     struct drm_debugfs_entry *entry = s->private;
> > +     struct dpu_encoder_virt *dpu_enc = entry->file.data;
> >       int i;
> >
> >       mutex_lock(&dpu_enc->enc_lock);
> > @@ -2110,48 +2110,31 @@ static int _dpu_encoder_status_show(struct seq_file *s, void *data)
> >       return 0;
> >   }
> >
> > -DEFINE_SHOW_ATTRIBUTE(_dpu_encoder_status);
> > -
> > -static int _dpu_encoder_init_debugfs(struct drm_encoder *drm_enc)
> > +static void _dpu_encoder_init_debugfs(struct drm_encoder *drm_enc)
> >   {
> >       struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
> > -
> > -     char name[12];
> > +     char *name;
> >
> >       if (!drm_enc->dev) {
> >               DPU_ERROR("invalid encoder or kms\n");
> > -             return -EINVAL;
> > +             return;
> >       }
> >
> > -     snprintf(name, sizeof(name), "encoder%u", drm_enc->base.id);
> > +     name = devm_kasprintf(drm_enc->dev->dev, GFP_KERNEL, "encoder%u", drm_enc->base.id);
> >
> > -     /* create overall sub-directory for the encoder */
> > -     dpu_enc->debugfs_root = debugfs_create_dir(name,
> > -                     drm_enc->dev->primary->debugfs_root);
> > -
> > -     /* don't error check these */
> > -     debugfs_create_file("status", 0600,
> > -             dpu_enc->debugfs_root, dpu_enc, &_dpu_encoder_status_fops);
> > -
> > -     return 0;
> > +     drm_debugfs_add_file(drm_enc->dev, name, _dpu_encoder_status_show, dpu_enc);
> >   }
> >   #else
> > -static int _dpu_encoder_init_debugfs(struct drm_encoder *drm_enc)
> > +static void _dpu_encoder_init_debugfs(struct drm_encoder *drm_enc)
> >   {
> > -     return 0;
> >   }
> >   #endif
> >
> >   static int dpu_encoder_late_register(struct drm_encoder *encoder)
> >   {
> > -     return _dpu_encoder_init_debugfs(encoder);
> > -}
> > -
> > -static void dpu_encoder_early_unregister(struct drm_encoder *encoder)
> > -{
> > -     struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(encoder);
> > +     _dpu_encoder_init_debugfs(encoder);
> >
> > -     debugfs_remove_recursive(dpu_enc->debugfs_root);
> > +     return 0;
> >   }
> >
> >   static int dpu_encoder_virt_add_phys_encs(
> > @@ -2380,7 +2363,6 @@ static const struct drm_encoder_helper_funcs dpu_encoder_helper_funcs = {
> >   static const struct drm_encoder_funcs dpu_encoder_funcs = {
> >               .destroy = dpu_encoder_destroy,
> >               .late_register = dpu_encoder_late_register,
> > -             .early_unregister = dpu_encoder_early_unregister,
> >   };
> >
> >   int dpu_encoder_setup(struct drm_device *dev, struct drm_encoder *enc,



-- 
With best wishes
Dmitry