drm/fbdev-dma: Only install deferred I/O if necessary
Deferred I/O requires struct page for framebuffer memory, which is not guaranteed for all DMA ranges. We thus only install deferred I/O if we have a framebuffer that requires it. A reported bug affected the ipu-v3 and pl111 drivers, which have video memory in either Normal or HighMem zones [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000010000000-0x000000003fffffff] [ 0.000000] HighMem [mem 0x0000000040000000-0x000000004fffffff] where deferred I/O only works correctly with HighMem. See the Closes tags for bug reports. v2: - test if screen_buffer supports deferred I/O (Sima) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 808a40b6 ("drm/fbdev-dma: Implement damage handling and deferred I/O") Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com> Closes: https://lore.kernel.org/all/23636953.6Emhk5qWAg@steina-w/Reported-by: Linus Walleij <linus.walleij@linaro.org> Closes: https://lore.kernel.org/dri-devel/CACRpkdb+hb9AGavbWpY-=uQQ0apY9en_tWJioPKf_fAbXMP4Hg@mail.gmail.com/Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> Tested-by: Linus Walleij <linus.walleij@linaro.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Javier Martinez Canillas <javierm@redhat.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240904123750.31206-1-tzimmermann@suse.de
Showing
Please register or sign in to comment