user/sven/linux.git/include/linux/fb.h, branch v5.16.19

fbdev: Hot-unplug firmware fb devices on forced removal

2022-04-08T12:05:31Z

commit 27599aacbaefcbf2af7b06b0029459bbf682000d upstream. Hot-unplug all firmware-framebuffer devices as part of removing them via remove_conflicting_framebuffers() et al. Releases all memory regions to be acquired by native drivers. Firmware, such as EFI, install a framebuffer while posting the computer. After removing the firmware-framebuffer device from fbdev, a native driver takes over the hardware and the firmware framebuffer becomes invalid. Firmware-framebuffer drivers, specifically simplefb, don't release their device from Linux' device hierarchy. It still owns the firmware framebuffer and blocks the native drivers from loading. This has been observed in the vmwgfx driver. [1] Initiating a device removal (i.e., hot unplug) as part of remove_conflicting_framebuffers() removes the underlying device and returns the memory range to the system. [1] https://lore.kernel.org/dri-devel/20220117180359.18114-1-zack@kde.org/ v2: * rename variable 'dev' to 'device' (Javier) Signed-off-by: Thomas Zimmermann Reported-by: Zack Rusin Reviewed-by: Javier Martinez Canillas Reviewed-by: Zack Rusin Reviewed-by: Hans de Goede CC: stable@vger.kernel.org # v5.11+ Link: https://patchwork.freedesktop.org/patch/msgid/20220125091222.21457-2-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman

Revert "fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)"

2022-02-08T17:35:11Z

commit 1148836fd3226c20de841084aba24184d4fbbe77 upstream. This reverts commit b3ec8cdf457e5e63d396fe1346cc788cf7c1b578. Revert the second (of 2) commits which disabled scrolling acceleration in fbcon/fbdev. It introduced a regression for fbdev-supported graphic cards because of the performance penalty by doing screen scrolling by software instead of using the existing graphic card 2D hardware acceleration. Console scrolling acceleration was disabled by dropping code which checked at runtime the driver hardware capabilities for the BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move screen contents. After dropping those checks scrollmode was hard-wired to SCROLL_REDRAW instead, which forces all graphic cards to redraw every character at the new screen position when scrolling. This change effectively disabled all hardware-based scrolling acceleration for ALL drivers, because now all kind of 2D hardware acceleration (bitblt, fillrect) in the drivers isn't used any longer. The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm and gma500) used hardware acceleration in the past and thus code for checking and using scrolling acceleration is obsolete. This statement is NOT TRUE, because beside the DRM drivers there are around 35 other fbdev drivers which depend on fbdev/fbcon and still provide hardware acceleration for fbdev/fbcon. The original commit message also states that syzbot found lots of bugs in fbcon and thus it's "often the solution to just delete code and remove features". This is true, and the bugs - which actually affected all users of fbcon, including DRM - were fixed, or code was dropped like e.g. the support for software scrollback in vgacon (commit 973c096f6a85). So to further analyze which bugs were found by syzbot, I've looked through all patches in drivers/video which were tagged with syzbot or syzkaller back to year 2005. The vast majority fixed the reported issues on a higher level, e.g. when screen is to be resized, or when font size is to be changed. The few ones which touched driver code fixed a real driver bug, e.g. by adding a check. But NONE of those patches touched code of either the SCROLL_MOVE or the SCROLL_REDRAW case. That means, there was no real reason why SCROLL_MOVE had to be ripped-out and just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it could go away. That argument completely missed the fact that SCROLL_MOVE is still heavily used by fbdev (non-DRM) drivers. Some people mention that using memcpy() instead of the hardware acceleration is pretty much the same speed. But that's not true, at least not for older graphic cards and machines where we see speed decreases by factor 10 and more and thus this change leads to console responsiveness way worse than before. That's why the original commit is to be reverted. By reverting we reintroduce hardware-based scrolling acceleration and fix the performance regression for fbdev drivers. There isn't any impact on DRM when reverting those patches. Signed-off-by: Helge Deller Acked-by: Geert Uytterhoeven Acked-by: Sven Schnelle Cc: stable@vger.kernel.org # v5.16+ Signed-off-by: Helge Deller Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-2-deller@gmx.de Signed-off-by: Greg Kroah-Hartman

fbdev: fbmem: add a helper to determine if an aperture is used by a fw fb

2021-12-31T13:57:45Z

Add a function for drivers to check if the a firmware initialized fb is corresponds to their aperture. This allows drivers to check if the device corresponds to what the firmware set up as the display device. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=215203 Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1840 Signed-off-by: Alex Deucher

fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)

2021-10-13T13:29:23Z

Scroll acceleration is disabled in fbcon by hard-wiring p->scrollmode = SCROLL_REDRAW. Remove the obsolete code in fbcon.c and fbdev/core/ Signed-off-by: Claudio Suarez Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/YVXTYqszZix9TxjJ@gineta.localdomain

Merge tag 'drm-misc-next-2021-07-22' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

2021-07-23T01:32:43Z

drm-misc-next for v5.15-rc1: UAPI Changes: - Remove sysfs stats for dma-buf attachments, as it causes a performance regression. Previous merge is not in a rc kernel yet, so no userspace regression possible. Cross-subsystem Changes: - Sanitize user input in kyro's viewport ioctl. - Use refcount_t in fb_info->count - Assorted fixes to dma-buf. - Extend x86 efifb handling to all archs. - Fix neofb divide by 0. - Document corpro,gm7123 bridge dt bindings. Core Changes: - Slightly rework drm master handling. - Cleanup vgaarb handling. - Assorted fixes. Driver Changes: - Add support for ws2401 panel. - Assorted fixes to stm, ast, bochs. - Demidlayer ingenic irq. Signed-off-by: Dave Airlie From: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/2d0d2fe8-01fc-e216-c3fd-38db9e69944e@linux.intel.com

fbmem: Convert from atomic_t to refcount_t on fb_info->count

2021-07-19T20:16:35Z

refcount_t type and corresponding API can protect refcounters from accidental underflow and overflow and further use-after-free situations. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/1626674392-55857-1-git-send-email-xiyuyang19@fudan.edu.cn

Revert "fb_defio: Remove custom address_space_operations"

2021-06-01T15:38:40Z

Commit ccf953d8f3d6 makes framebuffers which use deferred I/O stop displaying updates after the first one. This is because the pages handled by fb_defio no longer have a page_mapping(). That prevents page_mkclean() from marking the PTEs as clean, and so writes are only noticed the first time. Reported-by: Andy Shevchenko Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/YLZEhv0cpZp8uVE3@casper.infradead.org

fb_defio: Remove custom address_space_operations

2021-03-12T14:10:03Z

There's no need to give the page an address_space. Leaving the page->mapping as NULL will cause the VM to handle set_page_dirty() the same way that it's handled now, and that was the only reason to set the address_space in the first place. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: William Kucharski Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210310185530.1053320-1-willy@infradead.org

Merge drm/drm-next into drm-misc-next

2020-08-12T18:42:08Z

Backmerging drm-next into drm-misc-next for nouveau and panel updates. Resolves a conflict between ttm and nouveau, where struct ttm_mem_res got renamed to struct ttm_resource. Signed-off-by: Thomas Zimmermann

fbmem: pull fbcon_update_vcs() out of fb_set_var()

2020-08-04T05:37:23Z

syzbot is reporting OOB read bug in vc_do_resize() [1] caused by memcpy() based on outdated old_{rows,row_size} values, for resize_screen() can recurse into vc_do_resize() which changes vc->vc_{cols,rows} that outdates old_{rows,row_size} values which were saved before calling resize_screen(). Daniel Vetter explained that resize_screen() should not recurse into fbcon_update_vcs() path due to FBINFO_MISC_USEREVENT being still set when calling resize_screen(). Instead of masking FBINFO_MISC_USEREVENT before calling fbcon_update_vcs(), we can remove FBINFO_MISC_USEREVENT by calling fbcon_update_vcs() only if fb_set_var() returned 0. This change assumes that it is harmless to call fbcon_update_vcs() when fb_set_var() returned 0 without reaching fb_notifier_call_chain(). [1] https://syzkaller.appspot.com/bug?id=c70c88cfd16dcf6e1d3c7f0ab8648b3144b5b25e Reported-and-tested-by: syzbot Suggested-by: Daniel Vetter Signed-off-by: Tetsuo Handa Reported-by: kernel test robot for missing #include Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/075b7e37-3278-cd7d-31ab-c5073cfa8e92@i-love.sakura.ne.jp