[PATCH v3] drm: Improve the output_poll_changed description

[PATCH v3] drm: Improve the output_poll_changed description

[ZhiJie.Zhang]

From: zhangzhijie <zhangzhijie@loongson.cn>

this callback was used by drm_kms_helper_hotplug_event()

V2: (Thanks for Daniel's suggestions)
- remove the FIXME below.since with the drm_client
- infrastructure and the generic fbdev emulation we've
- resolved this all very neatly now.

V3: Add comments that This hook is deprecated
- new implementation methods instead of this hook

Signed-off-by: zhangzhijie <zhangzhijie@loongson.cn>
Signed-off-by: ZhiJie.Zhang <zhangzhijie@loongson.cn>
---
 include/drm/drm_mode_config.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index ab424ddd7665..a084482d579a 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -103,14 +103,14 @@ struct drm_mode_config_funcs {
 	 * Callback used by helpers to inform the driver of output configuration
 	 * changes.
 	 *
-	 * Drivers implementing fbdev emulation with the helpers can call
-	 * drm_fb_helper_hotplug_changed from this hook to inform the fbdev
+	 * Drivers implementing fbdev emulation with the helpers. Drivers use
+	 * drm_kms_helper_hotplug_event() to call this hook to inform the fbdev
 	 * helper of output changes.
 	 *
-	 * FIXME:
-	 *
-	 * Except that there's no vtable for device-level helper callbacks
-	 * there's no reason this is a core function.
+	 * This hook is deprecated, drivers should instead use
+	 * drm_fbdev_generic_setup() which takes care of any necessary
+	 * hotplug event forwarding already without further involvement by
+	 * the driver.
 	 */
 	void (*output_poll_changed)(struct drm_device *dev);
 
-- 
2.29.2

Re: [PATCH v3] drm: Improve the output_poll_changed description

[Thomas Zimmermann]

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Hi

Am 18.01.21 um 02:22 schrieb ZhiJie.Zhang:
> From: zhangzhijie <zhangzhijie@loongson.cn>
> 
> this callback was used by drm_kms_helper_hotplug_event()
> 
> V2: (Thanks for Daniel's suggestions)
> - remove the FIXME below.since with the drm_client
> - infrastructure and the generic fbdev emulation we've
> - resolved this all very neatly now.
> 
> V3: Add comments that This hook is deprecated
> - new implementation methods instead of this hook
> 
> Signed-off-by: zhangzhijie <zhangzhijie@loongson.cn>
> Signed-off-by: ZhiJie.Zhang <zhangzhijie@loongson.cn>
> ---
>   include/drm/drm_mode_config.h | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index ab424ddd7665..a084482d579a 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -103,14 +103,14 @@ struct drm_mode_config_funcs {
>   	 * Callback used by helpers to inform the driver of output configuration
>   	 * changes.
>   	 *
> -	 * Drivers implementing fbdev emulation with the helpers can call
> -	 * drm_fb_helper_hotplug_changed from this hook to inform the fbdev
> +	 * Drivers implementing fbdev emulation with the helpers. Drivers use
> +	 * drm_kms_helper_hotplug_event() to call this hook to inform the fbdev

I don't understand this. Maybe it's "Drivers implementing fbdev 
emulation use drm_kms_helper_hotplug_event() to call ..." ?

Best regards
Thomas

>   	 * helper of output changes.
>   	 *
> -	 * FIXME:
> -	 *
> -	 * Except that there's no vtable for device-level helper callbacks
> -	 * there's no reason this is a core function.
> +	 * This hook is deprecated, drivers should instead use
> +	 * drm_fbdev_generic_setup() which takes care of any necessary
> +	 * hotplug event forwarding already without further involvement by
> +	 * the driver.
>   	 */
>   	void (*output_poll_changed)(struct drm_device *dev);
>   
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer


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Re: [PATCH v3] drm: Improve the output_poll_changed description

[Daniel Vetter]

On Mon, Jan 18, 2021 at 7:53 AM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> Hi
>
> Am 18.01.21 um 02:22 schrieb ZhiJie.Zhang:
> > From: zhangzhijie <zhangzhijie@loongson.cn>
> >
> > this callback was used by drm_kms_helper_hotplug_event()
> >
> > V2: (Thanks for Daniel's suggestions)
> > - remove the FIXME below.since with the drm_client
> > - infrastructure and the generic fbdev emulation we've
> > - resolved this all very neatly now.
> >
> > V3: Add comments that This hook is deprecated
> > - new implementation methods instead of this hook
> >
> > Signed-off-by: zhangzhijie <zhangzhijie@loongson.cn>
> > Signed-off-by: ZhiJie.Zhang <zhangzhijie@loongson.cn>
> > ---
> >   include/drm/drm_mode_config.h | 12 ++++++------
> >   1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> > index ab424ddd7665..a084482d579a 100644
> > --- a/include/drm/drm_mode_config.h
> > +++ b/include/drm/drm_mode_config.h
> > @@ -103,14 +103,14 @@ struct drm_mode_config_funcs {
> >        * Callback used by helpers to inform the driver of output configuration
> >        * changes.
> >        *
> > -      * Drivers implementing fbdev emulation with the helpers can call
> > -      * drm_fb_helper_hotplug_changed from this hook to inform the fbdev
> > +      * Drivers implementing fbdev emulation with the helpers. Drivers use
> > +      * drm_kms_helper_hotplug_event() to call this hook to inform the fbdev
>
> I don't understand this. Maybe it's "Drivers implementing fbdev
> emulation use drm_kms_helper_hotplug_event() to call ..." ?

Yeah this just doesn't make sense now, this is not the interesting
information. Removing the hint that this should be implemented using
drm_fb_helper_hotplug_changed is really not good.
-Daniel

>
> Best regards
> Thomas
>
> >        * helper of output changes.
> >        *
> > -      * FIXME:
> > -      *
> > -      * Except that there's no vtable for device-level helper callbacks
> > -      * there's no reason this is a core function.
> > +      * This hook is deprecated, drivers should instead use
> > +      * drm_fbdev_generic_setup() which takes care of any necessary
> > +      * hotplug event forwarding already without further involvement by
> > +      * the driver.
> >        */
> >       void (*output_poll_changed)(struct drm_device *dev);
> >
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Geschäftsführer: Felix Imendörffer
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch