Re: [PATCH 24/33] Revert "backlight/fbcon: Add FB_EVENT_CONBLANK"

From: Daniel Thompson
Date: Fri May 24 2019 - 09:17:59 EST

On Fri, May 24, 2019 at 10:53:45AM +0200, Daniel Vetter wrote:
> This reverts commit 994efacdf9a087b52f71e620b58dfa526b0cf928.
>
> The justification is that if hw blanking fails (i.e. fbops->fb_blank)
> fails, then we still want to shut down the backlight. Which is exactly
> _not_ what fb_blank() does and so rather inconsistent if we end up
> with different behaviour between fbcon and direct fbdev usage. Given
> that the entire notifier maze is getting in the way anyway I figured
> it's simplest to revert this not well justified commit.
>
> v2: Add static inline to the dummy version.
>
> Cc: Richard Purdie <rpurdie@xxxxxxxxx>
> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> Cc: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> Cc: Jingoo Han <jingoohan1@xxxxxxxxx>
> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
> Cc: Yisheng Xie <ysxie@xxxxxxxxxxx>
> Cc: linux-fbdev@xxxxxxxxxxxxxxx

Hi Daniel

When this goes round again could you add me to the covering letter?

I looked at all three of the patches and no objections on my side but
I'm reluctant to send out acks because I'm not sure I understood the
wider picture well enough.


Daniel.


> ---
> drivers/video/backlight/backlight.c | 2 +-
> drivers/video/fbdev/core/fbcon.c | 14 +-------------
> drivers/video/fbdev/core/fbmem.c | 1 +
> include/linux/fb.h | 4 +---
> include/linux/fbcon.h | 2 ++
> 5 files changed, 6 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
> index deb824bef6e2..c55590ec0057 100644
> --- a/drivers/video/backlight/backlight.c
> +++ b/drivers/video/backlight/backlight.c
> @@ -46,7 +46,7 @@ static int fb_notifier_callback(struct notifier_block *self,
> int fb_blank = 0;
>
> /* If we aren't interested in this event, skip it immediately ... */
> - if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
> + if (event != FB_EVENT_BLANK)
> return 0;
>
> bd = container_of(self, struct backlight_device, fb_notif);
> diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
> index 259cdd118475..d9f545f1a81b 100644
> --- a/drivers/video/fbdev/core/fbcon.c
> +++ b/drivers/video/fbdev/core/fbcon.c
> @@ -2350,8 +2350,6 @@ static int fbcon_switch(struct vc_data *vc)
> static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
> int blank)
> {
> - struct fb_event event;
> -
> if (blank) {
> unsigned short charmask = vc->vc_hi_font_mask ?
> 0x1ff : 0xff;
> @@ -2362,13 +2360,6 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
> fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
> vc->vc_video_erase_char = oldc;
> }
> -
> -
> - lock_fb_info(info);
> - event.info = info;
> - event.data = &blank;
> - fb_notifier_call_chain(FB_EVENT_CONBLANK, &event);
> - unlock_fb_info(info);
> }
>
> static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)
> @@ -3240,7 +3231,7 @@ int fbcon_fb_registered(struct fb_info *info)
> return ret;
> }
>
> -static void fbcon_fb_blanked(struct fb_info *info, int blank)
> +void fbcon_fb_blanked(struct fb_info *info, int blank)
> {
> struct fbcon_ops *ops = info->fbcon_par;
> struct vc_data *vc;
> @@ -3344,9 +3335,6 @@ static int fbcon_event_notify(struct notifier_block *self,
> con2fb = event->data;
> con2fb->framebuffer = con2fb_map[con2fb->console - 1];
> break;
> - case FB_EVENT_BLANK:
> - fbcon_fb_blanked(info, *(int *)event->data);
> - break;
> case FB_EVENT_REMAP_ALL_CONSOLE:
> idx = info->node;
> fbcon_remap_all(idx);
> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
> index ddc0c16b8bbf..9366fbe99a58 100644
> --- a/drivers/video/fbdev/core/fbmem.c
> +++ b/drivers/video/fbdev/core/fbmem.c
> @@ -1068,6 +1068,7 @@ fb_blank(struct fb_info *info, int blank)
> event.data = &blank;
>
> early_ret = fb_notifier_call_chain(FB_EARLY_EVENT_BLANK, &event);
> + fbcon_fb_blanked(info, blank);
>
> if (info->fbops->fb_blank)
> ret = info->fbops->fb_blank(blank, info);
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index 0d86aa31bf8d..1e66fac3124f 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -137,12 +137,10 @@ struct fb_cursor_user {
> #define FB_EVENT_GET_CONSOLE_MAP 0x07
> /* CONSOLE-SPECIFIC: set console to framebuffer mapping */
> #define FB_EVENT_SET_CONSOLE_MAP 0x08
> -/* A hardware display blank change occurred */
> +/* A display blank is requested */
> #define FB_EVENT_BLANK 0x09
> /* Private modelist is to be replaced */
> #define FB_EVENT_MODE_CHANGE_ALL 0x0B
> -/* A software display blank change occurred */
> -#define FB_EVENT_CONBLANK 0x0C
> /* CONSOLE-SPECIFIC: remap all consoles to new fb - for vga_switcheroo */
> #define FB_EVENT_REMAP_ALL_CONSOLE 0x0F
> /* A hardware display blank early change occurred */
> diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h
> index 305e4f2eddac..d67d7ec51ef9 100644
> --- a/include/linux/fbcon.h
> +++ b/include/linux/fbcon.h
> @@ -14,6 +14,7 @@ int fbcon_mode_deleted(struct fb_info *info,
> void fbcon_new_modelist(struct fb_info *info);
> void fbcon_get_requirement(struct fb_info *info,
> struct fb_blit_caps *caps);
> +void fbcon_fb_blanked(struct fb_info *info, int blank);
> #else
> static inline void fb_console_init(void) {}
> static inline void fb_console_exit(void) {}
> @@ -27,6 +28,7 @@ static inline int fbcon_mode_deleted(struct fb_info *info,
> static inline void fbcon_new_modelist(struct fb_info *info) {}
> static inline void fbcon_get_requirement(struct fb_info *info,
> struct fb_blit_caps *caps) {}
> +static inline void fbcon_fb_blanked(struct fb_info *info, int blank) {}
> #endif
>
> #endif /* _LINUX_FBCON_H */
> --
> 2.20.1
>