Re: [PATCH v2 4/5] drm/ast: Fail probing if DCC channel could not be initialized

[Patrik Jakobsson <patrik.r.jakobsson@gmail.com>]

On Thu, Jun 2, 2022 at 11:32 AM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> Hi Patrik
>
> Am 02.06.22 um 09:42 schrieb Patrik Jakobsson:
> > On Thu, Jun 2, 2022 at 9:25 AM Patrik Jakobsson
> > <patrik.r.jakobsson@gmail.com> wrote:
> >>
> >> On Tue, May 31, 2022 at 1:15 PM Thomas Zimmermann <tzimmermann@suse.de> wrote:
> >>>
> >>> Expect the hardware to provide a DDC channel. Fail probing if its
> >>> initialization fails.
> >>>
> >>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> >>
> >> It's funny how I just did the same thing to gma500. Great minds think alike ;)
> >>
> >> Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
> >
> > I just realized that the ast_i2c_chan is never freed. Could be fixed
> > in a follow-up patch?
>
> In ast_i2c_create(), there's a call to drmm_add_action_or_reset(), which
> sets up ast_i2c_release(), which in turn kfree's the memory. Unless I'm
> totally missing something here.

Oh, I missed that. Then never mind :)

>
> Best regards
> Thomas
>
> >
> >>
> >>
> >>> ---
> >>>   drivers/gpu/drm/ast/ast_drv.h  |  2 --
> >>>   drivers/gpu/drm/ast/ast_i2c.c  |  7 ++++---
> >>>   drivers/gpu/drm/ast/ast_mode.c | 38 ++++++++++++++++------------------
> >>>   3 files changed, 22 insertions(+), 25 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
> >>> index 3055b0be7b67..2a55fc7303b9 100644
> >>> --- a/drivers/gpu/drm/ast/ast_drv.h
> >>> +++ b/drivers/gpu/drm/ast/ast_drv.h
> >>> @@ -132,7 +132,6 @@ struct ast_i2c_chan {
> >>>
> >>>   struct ast_vga_connector {
> >>>          struct drm_connector base;
> >>> -       struct ast_i2c_chan *i2c;
> >>>   };
> >>>
> >>>   static inline struct ast_vga_connector *
> >>> @@ -143,7 +142,6 @@ to_ast_vga_connector(struct drm_connector *connector)
> >>>
> >>>   struct ast_sil164_connector {
> >>>          struct drm_connector base;
> >>> -       struct ast_i2c_chan *i2c;
> >>>   };
> >>>
> >>>   static inline struct ast_sil164_connector *
> >>> diff --git a/drivers/gpu/drm/ast/ast_i2c.c b/drivers/gpu/drm/ast/ast_i2c.c
> >>> index 93e91c36d649..1d039ff1396e 100644
> >>> --- a/drivers/gpu/drm/ast/ast_i2c.c
> >>> +++ b/drivers/gpu/drm/ast/ast_i2c.c
> >>> @@ -117,7 +117,7 @@ struct ast_i2c_chan *ast_i2c_create(struct drm_device *dev)
> >>>
> >>>          i2c = kzalloc(sizeof(struct ast_i2c_chan), GFP_KERNEL);
> >>>          if (!i2c)
> >>> -               return NULL;
> >>> +               return ERR_PTR(-ENOMEM);
> >>>
> >>>          i2c->adapter.owner = THIS_MODULE;
> >>>          i2c->adapter.class = I2C_CLASS_DDC;
> >>> @@ -143,10 +143,11 @@ struct ast_i2c_chan *ast_i2c_create(struct drm_device *dev)
> >>>
> >>>          ret = drmm_add_action_or_reset(dev, ast_i2c_release, i2c);
> >>>          if (ret)
> >>> -               return NULL;
> >>> +               return ERR_PTR(ret);
> >>> +
> >>>          return i2c;
> >>>
> >>>   out_kfree:
> >>>          kfree(i2c);
> >>> -       return NULL;
> >>> +       return ERR_PTR(ret);
> >>>   }
> >>> diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
> >>> index bbc566c4c768..5f273b5dd769 100644
> >>> --- a/drivers/gpu/drm/ast/ast_mode.c
> >>> +++ b/drivers/gpu/drm/ast/ast_mode.c
> >>> @@ -1334,19 +1334,18 @@ static int ast_vga_connector_init(struct drm_device *dev,
> >>>                                    struct ast_vga_connector *ast_vga_connector)
> >>>   {
> >>>          struct drm_connector *connector = &ast_vga_connector->base;
> >>> +       struct ast_i2c_chan *i2c;
> >>>          int ret;
> >>>
> >>> -       ast_vga_connector->i2c = ast_i2c_create(dev);
> >>> -       if (!ast_vga_connector->i2c)
> >>> -               drm_err(dev, "failed to add ddc bus for connector\n");
> >>> +       i2c = ast_i2c_create(dev);
> >>> +       if (IS_ERR(i2c)) {
> >>> +               ret = PTR_ERR(i2c);
> >>> +               drm_err(dev, "failed to add ddc bus for connector; ret=%d\n", ret);
> >>> +               return ret;
> >>> +       }
> >>>
> >>> -       if (ast_vga_connector->i2c)
> >>> -               ret = drm_connector_init_with_ddc(dev, connector, &ast_vga_connector_funcs,
> >>> -                                                 DRM_MODE_CONNECTOR_VGA,
> >>> -                                                 &ast_vga_connector->i2c->adapter);
> >>> -       else
> >>> -               ret = drm_connector_init(dev, connector, &ast_vga_connector_funcs,
> >>> -                                        DRM_MODE_CONNECTOR_VGA);
> >>> +       ret = drm_connector_init_with_ddc(dev, connector, &ast_vga_connector_funcs,
> >>> +                                         DRM_MODE_CONNECTOR_VGA, &i2c->adapter);
> >>>          if (ret)
> >>>                  return ret;
> >>>
> >>> @@ -1406,19 +1405,18 @@ static int ast_sil164_connector_init(struct drm_device *dev,
> >>>                                       struct ast_sil164_connector *ast_sil164_connector)
> >>>   {
> >>>          struct drm_connector *connector = &ast_sil164_connector->base;
> >>> +       struct ast_i2c_chan *i2c;
> >>>          int ret;
> >>>
> >>> -       ast_sil164_connector->i2c = ast_i2c_create(dev);
> >>> -       if (!ast_sil164_connector->i2c)
> >>> -               drm_err(dev, "failed to add ddc bus for connector\n");
> >>> +       i2c = ast_i2c_create(dev);
> >>> +       if (IS_ERR(i2c)) {
> >>> +               ret = PTR_ERR(i2c);
> >>> +               drm_err(dev, "failed to add ddc bus for connector; ret=%d\n", ret);
> >>> +               return ret;
> >>> +       }
> >>>
> >>> -       if (ast_sil164_connector->i2c)
> >>> -               ret = drm_connector_init_with_ddc(dev, connector, &ast_sil164_connector_funcs,
> >>> -                                                 DRM_MODE_CONNECTOR_DVII,
> >>> -                                                 &ast_sil164_connector->i2c->adapter);
> >>> -       else
> >>> -               ret = drm_connector_init(dev, connector, &ast_sil164_connector_funcs,
> >>> -                                        DRM_MODE_CONNECTOR_DVII);
> >>> +       ret = drm_connector_init_with_ddc(dev, connector, &ast_sil164_connector_funcs,
> >>> +                                         DRM_MODE_CONNECTOR_DVII, &i2c->adapter);
> >>>          if (ret)
> >>>                  return ret;
> >>>
> >>> --
> >>> 2.36.1
> >>>
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Ivo Totev