linux/drivers/video/fbdev/ps3fb.c

1304 lines
33 KiB

ps3fb: fix deadlock on kexec() Since the introduction of the acquire_console_sem calls in 0333d83509c7d8496c8965b5ba9bc0c98e83c259, kexecing can cause the kernel to deadlock: ps3fb_shutdown() -> unregister_framebuffer() -> fb_notifier_call_chain(FB_EVENT_FB_UNBIND) -> fbcon_fb_unbind() -> unbind_con_driver() -> bind_con_driver() [ acquires console_sem ] -> fbcon_deinit() -> fbops->fb_release(newinfo, 0) -> ps3fb_release() -> ps3fb_sync() [ acquires console_sem ] This change avoids the deadlock by moving the acquire_console_sem() out of ps3fb_sync(), and puts it into the two other callsites, leaving ps3fb_release() to call ps3fb_sync() without the console semaphore. [Geert] - Corrected call sequence above - ps3fb_release() may be called with and without console_sem held. This is an inconsistency that should be fixed at the fb level, but for now, try to acquire console_sem in ps3fb_release(). I think it's safer to let ps3fb_release() try to acquire console_sem and not refresh the screen if it fails, than to call ps3fb_sync() without holding console_sem, as ps3fb_par may be modified at the same time, causing crashes or lockups. Besides, ps3fb_release() only calls ps3fb_sync() to refresh the screen when display flipping is disabled, which is an uncommon case (except during shutdown/kexec). Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-11 14:28:04 +01:00
ps3fb: fix deadlock on kexec() Since the introduction of the acquire_console_sem calls in 0333d83509c7d8496c8965b5ba9bc0c98e83c259, kexecing can cause the kernel to deadlock: ps3fb_shutdown() -> unregister_framebuffer() -> fb_notifier_call_chain(FB_EVENT_FB_UNBIND) -> fbcon_fb_unbind() -> unbind_con_driver() -> bind_con_driver() [ acquires console_sem ] -> fbcon_deinit() -> fbops->fb_release(newinfo, 0) -> ps3fb_release() -> ps3fb_sync() [ acquires console_sem ] This change avoids the deadlock by moving the acquire_console_sem() out of ps3fb_sync(), and puts it into the two other callsites, leaving ps3fb_release() to call ps3fb_sync() without the console semaphore. [Geert] - Corrected call sequence above - ps3fb_release() may be called with and without console_sem held. This is an inconsistency that should be fixed at the fb level, but for now, try to acquire console_sem in ps3fb_release(). I think it's safer to let ps3fb_release() try to acquire console_sem and not refresh the screen if it fails, than to call ps3fb_sync() without holding console_sem, as ps3fb_par may be modified at the same time, causing crashes or lockups. Besides, ps3fb_release() only calls ps3fb_sync() to refresh the screen when display flipping is disabled, which is an uncommon case (except during shutdown/kexec). Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-11 14:28:04 +01:00
fbdev/ps3fb: Build without kernel device Use fb_info() to print status message at the end of the probe function, which avoids decoding the devices. fb_info() works with or without an fbdev kernel device. Fixes the following error: ../drivers/video/fbdev/ps3fb.c: In function 'ps3fb_probe': ../drivers/video/fbdev/ps3fb.c:1172:40: error: 'struct fb_info' has no member named 'dev' 1172 | dev_driver_string(info->dev), dev_name(info->dev), | ^~ ../include/linux/dev_printk.h:110:37: note: in definition of macro 'dev_printk_index_wrap' 110 | _p_func(dev, fmt, ##__VA_ARGS__); \ | ^~~~~~~~~~~ ../drivers/video/fbdev/ps3fb.c:1171:9: note: in expansion of macro 'dev_info' 1171 | dev_info(info->device, "%s %s, using %u KiB of video memory\n", | ^~~~~~~~ ../drivers/video/fbdev/ps3fb.c:1172:61: error: 'struct fb_info' has no member named 'dev' 1172 | dev_driver_string(info->dev), dev_name(info->dev), | ^~ ../include/linux/dev_printk.h:110:37: note: in definition of macro 'dev_printk_index_wrap' 110 | _p_func(dev, fmt, ##__VA_ARGS__); \ | ^~~~~~~~~~~ ../drivers/video/fbdev/ps3fb.c:1171:9: note: in expansion of macro 'dev_info' 1171 | dev_info(info->device, "%s %s, using %u KiB of video memory\n", | ^~~~~~~~ Reported-by: Randy Dunlap <rdunlap@infradead.org> Closes: https://lore.kernel.org/lkml/ccc63065-2976-88ef-1211-731330bf2866@infradead.org/ Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 701d2054fa31 ("fbdev: Make support for userspace interfaces configurable") Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Helge Deller <deller@gmx.de> Cc: Javier Martinez Canillas <javierm@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Link: https://patchwork.freedesktop.org/patch/msgid/20230731175535.11345-1-tzimmermann@suse.de
2023-07-31 19:55:00 +02:00