Hi Javier
Am 07.06.22 um 20:23 schrieb Javier Martinez Canillas:
From: Daniel Vetter daniel.vetter@ffwll.ch
Well except when the olpc dcon fbdev driver is enabled, that thing digs around in there in rather unfixable ways.
There is fb_client_register() to set up a 'client' on top of an fbdev. The client would then get messages about modesetting, blanks, removals, etc. But you'd probably need an OLPC to convert dcon, and the mechanism itself is somewhat unloved these days.
Your patch complicates the fbdev code AFAICT. So I'd either drop it or, even better, build a nicer interface for dcon.
The dcon driver appears to look only at the first entry. Maybe add fb_info_get_by_index() and fb_info_put() and export those. They would be trivial wrappers somewhere in fbmem.c:
#if IS_ENABLED(CONFIG_FB_OLPC_DCON) struct fb_info *fb_info_get_by_index(unsigned int index) { return get_fb_info(index); } EXPORT_SYMBOL() void fb_info_put(struct fb_info *fb_info) { put_fb_info(fb_info); } EXPORT_SYMBOL() #endif
In dcon itself, using the new interfaces will actually acquire a reference to keep the display alive. The code at [1] could be replaced. And a call to fb_info_put() needs to go into dcon_remove(). [2]
Best regards Thomas
[1] https://elixir.bootlin.com/linux/v5.18.2/source/drivers/staging/olpc_dcon/ol... [2] https://elixir.bootlin.com/linux/v5.18.2/source/drivers/staging/olpc_dcon/ol...
Cc oldc_dcon maintainers as fyi.
v2: I typoed the config name (0day)
Cc: kernel test robot lkp@intel.com Cc: Jens Frederich jfrederich@gmail.com Cc: Jon Nettleton jon.nettleton@gmail.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: linux-staging@lists.linux.dev Signed-off-by: Daniel Vetter daniel.vetter@intel.com Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch Reviewed-by: Javier Martinez Canillas javierm@redhat.com Cc: Daniel Vetter daniel@ffwll.ch Cc: Helge Deller deller@gmx.de Cc: Matthew Wilcox willy@infradead.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Tetsuo Handa penguin-kernel@i-love.sakura.ne.jp Cc: Zhen Lei thunder.leizhen@huawei.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Xiyu Yang xiyuyang19@fudan.edu.cn Cc: linux-fbdev@vger.kernel.org Cc: Zheyu Ma zheyuma97@gmail.com Cc: Guenter Roeck linux@roeck-us.net Signed-off-by: Javier Martinez Canillas javierm@redhat.com
(no changes since v1)
drivers/video/fbdev/core/fbmem.c | 8 ++++++-- include/linux/fb.h | 7 +++---- 2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index e0720fef0ee6..bdb08b665b43 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -50,10 +50,14 @@ static DEFINE_MUTEX(registration_lock);
struct fb_info *registered_fb[FB_MAX] __read_mostly; -EXPORT_SYMBOL(registered_fb);
- int num_registered_fb __read_mostly;
+#if IS_ENABLED(CONFIG_FB_OLPC_DCON) +EXPORT_SYMBOL(registered_fb); EXPORT_SYMBOL(num_registered_fb); +#endif +#define for_each_registered_fb(i) \
for (i = 0; i < FB_MAX; i++) \
if (!registered_fb[i]) {} elsebool fb_center_logo __read_mostly;
diff --git a/include/linux/fb.h b/include/linux/fb.h index bbe1e4571899..c563e24b6293 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -632,16 +632,15 @@ extern int fb_get_color_depth(struct fb_var_screeninfo *var, extern int fb_get_options(const char *name, char **option); extern int fb_new_modelist(struct fb_info *info);
+#if IS_ENABLED(CONFIG_FB_OLPC_DCON) extern struct fb_info *registered_fb[FB_MAX];
- extern int num_registered_fb;
+#endif extern bool fb_center_logo; extern int fb_logo_count; extern struct class *fb_class;
-#define for_each_registered_fb(i) \
- for (i = 0; i < FB_MAX; i++) \
if (!registered_fb[i]) {} else- static inline void lock_fb_info(struct fb_info *info) { mutex_lock(&info->lock);