Re: [PATCH 10/33] fbcon: call fbcon_fb_(un)registered directly

From: Daniel Vetter
Date: Tue May 21 2019 - 11:12:19 EST


On Mon, May 20, 2019 at 10:37:53AM +0200, Thomas Zimmermann wrote:
> Hi
>
> Am 20.05.19 um 10:33 schrieb Thomas Zimmermann:
> > Hi
> >
> > Am 20.05.19 um 10:21 schrieb Daniel Vetter:
> > ...
> >> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
> >> index fc3d34a8ea5b..ae2db31eeba7 100644
> >> --- a/drivers/video/fbdev/core/fbmem.c
> >> +++ b/drivers/video/fbdev/core/fbmem.c
> >> @@ -1660,7 +1660,6 @@ MODULE_PARM_DESC(lockless_register_fb,
> >> static int do_register_framebuffer(struct fb_info *fb_info)
> >> {
> >> int i, ret;
> >> - struct fb_event event;
> >> struct fb_videomode mode;
> >>
> >> if (fb_check_foreignness(fb_info))
> >> @@ -1723,7 +1722,6 @@ static int do_register_framebuffer(struct fb_info *fb_info)
> >> fb_add_videomode(&mode, &fb_info->modelist);
> >> registered_fb[i] = fb_info;
> >>
> >> - event.info = fb_info;
> >> if (!lockless_register_fb)
> >> console_lock();
> >> else
> >> @@ -1732,9 +1730,8 @@ static int do_register_framebuffer(struct fb_info *fb_info)
> >> ret = -ENODEV;
> >> goto unlock_console;
> >> }
> >> - ret = 0;
> >>
> >> - fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
> >> + ret = fbcon_fb_registered(fb_info);
> >
> > What about backlight drivers? [1] Apparently these also use the
> > notifiers. [2] From my understanding, backlight drivers would stop
> > working with this change.
>
> I just saw that backlight drivers only care about blanking and
> unblanking. Never mind then.

I did screw this up for one event for the mode changes. But should be
fixed in the next series.

I also added a patch to simplify the backlight/lcd notifier, since it
doesn't need to filter events anymore after this series - the only events
left are the ones backlight cares about.

Cheers, Daniel

>
> Best regards
> Thomas
>
> >
> > Best regards
> > Thomas
> >
> > [1]
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/video/backlight
> > [2]
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/video/backlight/backlight.c#n40
> >
> >> unlock_fb_info(fb_info);
> >> unlock_console:
> >> if (!lockless_register_fb)
> >> @@ -1771,7 +1768,6 @@ static int __unlink_framebuffer(struct fb_info *fb_info);
> >>
> >> static int do_unregister_framebuffer(struct fb_info *fb_info)
> >> {
> >> - struct fb_event event;
> >> int ret;
> >>
> >> ret = unbind_console(fb_info);
> >> @@ -1789,9 +1785,8 @@ static int do_unregister_framebuffer(struct fb_info *fb_info)
> >> registered_fb[fb_info->node] = NULL;
> >> num_registered_fb--;
> >> fb_cleanup_device(fb_info);
> >> - event.info = fb_info;
> >> console_lock();
> >> - fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
> >> + fbcon_fb_unregistered(fb_info);
> >> console_unlock();
> >>
> >> /* this may free fb info */
> >> diff --git a/include/linux/fb.h b/include/linux/fb.h
> >> index f52ef0ad6781..701abaf79c87 100644
> >> --- a/include/linux/fb.h
> >> +++ b/include/linux/fb.h
> >> @@ -136,10 +136,6 @@ struct fb_cursor_user {
> >> #define FB_EVENT_RESUME 0x03
> >> /* An entry from the modelist was removed */
> >> #define FB_EVENT_MODE_DELETE 0x04
> >> -/* A driver registered itself */
> >> -#define FB_EVENT_FB_REGISTERED 0x05
> >> -/* A driver unregistered itself */
> >> -#define FB_EVENT_FB_UNREGISTERED 0x06
> >> /* CONSOLE-SPECIFIC: get console to framebuffer mapping */
> >> #define FB_EVENT_GET_CONSOLE_MAP 0x07
> >> /* CONSOLE-SPECIFIC: set console to framebuffer mapping */
> >> diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h
> >> index f68a7db14165..94a71e9e1257 100644
> >> --- a/include/linux/fbcon.h
> >> +++ b/include/linux/fbcon.h
> >> @@ -4,9 +4,13 @@
> >> #ifdef CONFIG_FRAMEBUFFER_CONSOLE
> >> void __init fb_console_init(void);
> >> void __exit fb_console_exit(void);
> >> +int fbcon_fb_registered(struct fb_info *info);
> >> +void fbcon_fb_unregistered(struct fb_info *info);
> >> #else
> >> static inline void fb_console_init(void) {}
> >> static inline void fb_console_exit(void) {}
> >> +static inline int fbcon_fb_registered(struct fb_info *info) { return 0; }
> >> +static inline void fbcon_fb_unregistered(struct fb_info *info) {}
> >> #endif
> >>
> >> #endif /* _LINUX_FBCON_H */
> >>
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
> GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
> HRB 21284 (AG Nürnberg)
>




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