Changes in Kconfig

eabb0329 - fbdev: Refactoring the fbcon packed pixel drawing routines

Sun, 09 Mar 2025 18:47:15 +0000

fbdev: Refactoring the fbcon packed pixel drawing routinesThe original version duplicated more or less the same algorithms forboth system and i/o memory.In this version the drawing algorithms (copy/fill/blit) are separatefrom the memory access (system and i/o). The two parts are gettingcombined in the loadable module sources. This also makes it more robustagainst wrong memory access type or alignment mistakes as there's nodirect pointer access or arithmetic in the algorithm sources anymore.Due to liberal use of inlining the compiled result is a single functionin all 6 cases, without unnecessary function calls. Unlike earlier theuse of macros could be minimized as apparently both gcc and clang iscapable now to do the same with inline functions just as well.What wasn't quite the same in the two variants is the support for pixelorder reversing. This version is capable to do that for both system andI/O memory, and not only for the latter. As demand for low bits perpixel modes isn't high there's a configuration option to enable thisseparately for the CFB and SYS modules.The pixel reversing algorithm is different than earlier and was designedso that it can take advantage of bit order reversing instructions onarchitectures which have them. And even for higher bits per pixel modeslike four bpp.One of the shortcomings of the earlier version was the incompletesupport for foreign endian framebuffers. Now all three drawingalgorithms produce correct output on both endians with native andforeign framebuffers. This is one of the important differences even ifotherwise the algorithms don't look too different than before.All three routines work now with aligned native word accesses. As aconsequence blitting isn't limited to 32 bits on 64 bit architectures asit was before.The old routines silently assumed that rows are a multiple of the wordsize. Due to how the new routines function this isn't a requirement anymore and access will be done aligned regardless. However if theframebuffer is configured like that then some of the fast paths won't beavailable.As this code is supposed to be running on all supported architectures itwasn't optimized for a particular one. That doesn't mean I haven'tlooked at the disassembly. That's where I noticed that it isn't a goodidea to use the fallback bitreversing code for example.The low bits per pixel modes should be faster than before as the newroutines can blit 4 pixels at a time.On the higher bits per pixel modes I retained the specialized alignedroutines so it should be more or less the same, except on 64 bitarchitectures. There the blitting word size is double now which means 32BPP isn't done a single pixel a time now.The code was tested on x86, amd64, mips32 and mips64. The latter two inbig endian configuration. Originally thought I can get away with thefirst two, but with such bit twisting code byte ordering is tricky andnot really possible to get right without actually verifying it.While writing such routines isn't rocket science a lot of time was spenton making sure that pixel ordering, foreign byte order, various bits perpixels, cpu endianness and word size will give the expected result inall sorts of combinations without making it overly complicated or fullwith special cases.Signed-off-by: Zsolt Kajtar Signed-off-by: Helge Deller List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

8fc38062 - fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICE

Mon, 16 Dec 2024 07:42:47 +0000

fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICEDo not select BACKLIGHT_CLASS_DEVICE from FB_BACKLIGHT. The latteronly controls backlight support within fbdev core code and datastructures.Make fbdev drivers depend on BACKLIGHT_CLASS_DEVICE and let usersselect it explicitly. Fixes warnings about recursive dependencies,such aserror: recursive dependency detected! symbol BACKLIGHT_CLASS_DEVICE is selected by FB_BACKLIGHT symbol FB_BACKLIGHT is selected by FB_SH_MOBILE_LCDC symbol FB_SH_MOBILE_LCDC depends on FB_DEVICE symbol FB_DEVICE depends on FB_CORE symbol FB_CORE is selected by DRM_GEM_DMA_HELPER symbol DRM_GEM_DMA_HELPER is selected by DRM_PANEL_ILITEK_ILI9341 symbol DRM_PANEL_ILITEK_ILI9341 depends on BACKLIGHT_CLASS_DEVICEBACKLIGHT_CLASS_DEVICE is user-selectable, so making drivers adapt toit is the correct approach in any case. For most drivers, backlightsupport is also configurable separately.v3:- Select BACKLIGHT_CLASS_DEVICE in PowerMac defconfigs (Christophe)- Fix PMAC_BACKLIGHT module dependency corner cases (Christophe)v2:- s/BACKLIGHT_DEVICE_CLASS/BACKLIGHT_CLASS_DEVICE (Helge)- Fix fbdev driver-dependency corner case (Arnd)Signed-off-by: Thomas Zimmermann Reviewed-by: Arnd Bergmann Link: https://patchwork.freedesktop.org/patch/msgid/20241216074450.8590-2-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

01c0cce8 - drm/omapdrm: Fix console with deferred ops

Wed, 28 Feb 2024 06:35:32 +0000

drm/omapdrm: Fix console with deferred opsCommit 95da53d63dcf ("drm/omapdrm: Use regular fbdev I/O helpers")stopped console from updating for command mode displays because there isno damage handling in fb_sys_write() unlike we had earlier indrm_fb_helper_sys_write().Let's fix the issue by adding FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS andFB_DMAMEM_HELPERS_DEFERRED as suggested by Thomas. We cannot use theFB_DEFAULT_DEFERRED_OPS as fb_deferred_io_mmap() won't work properlyfor write-combine.Fixes: 95da53d63dcf ("drm/omapdrm: Use regular fbdev I/O helpers")Suggested-by: Thomas Zimmermann Reviewed-by: Thomas Zimmermann Signed-off-by: Tony Lindgren Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20240228063540.4444-3-tony@atomide.com List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

a3b6792e - video/cmdline: Introduce CONFIG_VIDEO for video= parameter

Thu, 18 Jan 2024 09:05:26 +0000

video/cmdline: Introduce CONFIG_VIDEO for video= parameterAdd CONFIG_VIDEO for common code in drivers/video/. Use the option toselect helpers for the video= parameter. Replaces CONFIG_VIDEO_CMDLINE.Other common code in drivers/video/ can be moved behind CONFIG_VIDEO,which will simplify the Kconfig rules.Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20240118090721.7995-2-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

8813e86f - fbdev: Remove default file-I/O implementations

Mon, 27 Nov 2023 13:16:01 +0000

fbdev: Remove default file-I/O implementationsDrop the default implementations for file read, write and mmapoperations. Each fbdev driver must now provide an implementationand select any necessary helpers. If no implementation has beenset, fbdev returns an errno code to user space. The code is thesame as if the operation had not been set in the file_operationsstruct.This change makes the fbdev helpers for I/O memory optional. Mostsystems only use system-memory framebuffers via DRM's fbdev emulation.v2: * warn once if I/O callbacks are missing (Javier)Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-33-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

27ad64ea - fbdev: Rename FB_SYS_FOPS token to FB_SYSMEM_FOPS

Mon, 27 Nov 2023 13:15:56 +0000

fbdev: Rename FB_SYS_FOPS token to FB_SYSMEM_FOPSRename the token to harmonize naming among various helpers. Forexample, I/O-memory helpers use FB_IOMEM_FOPS.Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-28-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

6b180f66 - fbdev: Provide I/O-memory helpers as module

Wed, 27 Sep 2023 07:26:34 +0000

fbdev: Provide I/O-memory helpers as moduleProvide helpers for accessing I/O memory in a helper module. The fbdevcore uses these helpers, so select the module unconditionally for fbdev.Drivers will later be able to select the module individually and thehelpers will become optional.Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20230927074722.6197-2-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

bb6c4507 - drm: fix up fbdev Kconfig defaults

Mon, 11 Sep 2023 20:52:53 +0000

drm: fix up fbdev Kconfig defaultsAs a result of the recent Kconfig reworks, the default settings for theframebuffer interfaces changed in unexpected ways:Configurations that leave CONFIG_FB disabled but use DRM now getDRM_FBDEV_EMULATION by default. This also turns on the deprecated /dev/fbdevice nodes for machines that don't actually want it.In turn, configurations that previously had DRM_FBDEV_EMULATION enablednow only get the /dev/fb front-end but not the more useful framebufferconsole, which is not selected any more.We had previously decided that any combination of the three frontends(FB_DEVICE, FRAMEBUFFER_CONSOLE and LOGO) should be selectable, but thenew default settings mean that a lot of defconfig files would have toget adapted.Change the defaults back to what they were in Linux 6.5: - Leave DRM_FBDEV_EMULATION turned off unless CONFIG_FB is enabled. Previously this was a hard dependency but now the two are independent. However, configurations that enable CONFIG_FB probably also want to keep the emulation for DRM, while those without FB presumably did that intentionally in the past. - Leave FB_DEVICE turned off for FB=n. Following the same logic, the deprecated option should not automatically get enabled here, most users that had FB turned off in the past do not want it, even if they want the console - Turn the FRAMEBUFFER_CONSOLE option on if DRM_FBDEV_EMULATION is set to avoid having to change defconfig files that relied on it being selected unconditionally in the past. This also makes sense since both LOGO and FB_DEVICE are now disabled by default for builds without CONFIG_FB, but DRM_FBDEV_EMULATION would make no sense if all three are disabled.Fixes: a5ae331edb02b ("drm: Drop select FRAMEBUFFER_CONSOLE for DRM_FBDEV_EMULATION")Fixes: 701d2054fa317 ("fbdev: Make support for userspace interfaces configurable")Reported-by: Geert Uytterhoeven Signed-off-by: Arnd Bergmann Reviewed-by: Javier Martinez Canillas Reviewed-by: Geert Uytterhoeven Acked-by: Thomas Zimmermann Signed-off-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20230911205338.2385278-1-arnd@kernel.org List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

ee057f97 - fbdev: Add Kconfig macro FB_IOMEM_HELPERS_DEFERRED

Mon, 28 Aug 2023 13:14:19 +0000

fbdev: Add Kconfig macro FB_IOMEM_HELPERS_DEFERREDThe new Kconfig macro FB_IOMEM_HELPERS_DEFERRED selects fbdev'shelpers for device I/O memory and deferred I/O. Drivers shoulduse it if they perform damage updates on device I/O memory.Signed-off-by: Thomas Zimmermann Acked-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20230828132131.29295-4-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

b21f187f - fbdev: Use _DMAMEM_ infix for DMA-memory helpers

Sat, 29 Jul 2023 19:26:48 +0000

fbdev: Use _DMAMEM_ infix for DMA-memory helpersChange the infix for fbdev's DMA-memory helpers from _DMA_ to_DMAMEM_. The helpers perform operations within DMA-able memory,but they don't perform DMA operations. Naming should make thisclear. Adapt all users. No functional changes.Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230729193157.15446-4-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

cd8a064f - fbdev: Use _SYSMEM_ infix for system-memory helpers

Sat, 29 Jul 2023 19:26:47 +0000

fbdev: Use _SYSMEM_ infix for system-memory helpersChange the infix for fbdev's system-memory helpers from _SYS_ to_SYSMEM_. The helpers perform operations within system memory, butnot on the state of the operating system itself. Naming should makethis clear. Adapt all users. No functional changes.Suggested-by: Helge Deller Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230729193157.15446-3-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

4520844b - fbdev: Use _IOMEM_ infix for I/O-memory helpers

Sat, 29 Jul 2023 19:26:46 +0000

fbdev: Use _IOMEM_ infix for I/O-memory helpersChange the infix for fbdev's I/O-memory helpers from _IO_ to _IOMEM_to distiguish them from other types of I/O, such as file operations.The helpers operate on memory ranges in the I/O address space and thenaming should make this clear. Adapt all users. No functional changes.Suggested-by: Helge Deller Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230729193157.15446-2-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

6f0f6941 - fbdev: Add fb_ops init macros for framebuffers in DMA-able memory

Fri, 07 Jul 2023 08:31:52 +0000

fbdev: Add fb_ops init macros for framebuffers in DMA-able memoryAdd initializer macros for struct fb_ops for framebuffers in DMA-ablememory areas. Also add a corresponding Kconfig token. As of now, thisis equivalent to system framebuffers and mostly useful for labelingdrivers correctly.A later patch may add a generic DMA-specific mmap operation. Linuxoffers a number of dma_mmap_*() helpers for different use cases.Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Acked-by: Maxime Ripard Cc: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230707083422.18691-2-tzimmermann@suse.de List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

55bffc81 - fbdev: Split frame buffer support in FB and FB_CORE symbols

Wed, 19 Jul 2023 08:15:37 +0000

fbdev: Split frame buffer support in FB and FB_CORE symbolsCurrently the CONFIG_FB option has to be enabled even if no legacy fbdevdrivers are needed (e.g: only to have support for framebuffer consoles).The DRM subsystem has a fbdev emulation layer, but depends on CONFIG_FBand so it can only be enabled if that dependency is enabled as well.That means fbdev drivers have to be explicitly disabled if users want toenable CONFIG_FB, only to use fbcon and/or the DRM fbdev emulation layer.This patch introduces a non-visible CONFIG_FB_CORE symbol that could beenabled just to have core support needed for CONFIG_DRM_FBDEV_EMULATION,allowing CONFIG_FB to be disabled (and automatically disabling all thefbdev drivers).Nothing from fb_backlight.o and fbmon.o is used by the DRM fbdev emulationlayer so these two objects can be compiled out when CONFIG_FB is disabled.Signed-off-by: Javier Martinez Canillas Reviewed-by: Arnd Bergmann Tested-by: Arnd Bergmann Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-4-javierm@redhat.com List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig

df791524 - fbdev: Move core fbdev symbols to a separate Kconfig file

Wed, 19 Jul 2023 08:15:36 +0000

fbdev: Move core fbdev symbols to a separate Kconfig fileThe drivers/video/fbdev/Kconfig defines both symbols for fbdev drivers andcore fbdev symbols, that can be enabled independently of the fbdev drivers.Split the Kconfig in two, one that only has the symbols for fbdev driversand another one that contains the fbdev core symbols.Suggested-by: Arnd Bergmann Signed-off-by: Javier Martinez Canillas Reviewed-by: Arnd Bergmann Tested-by: Arnd Bergmann Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-3-javierm@redhat.com List of files: /linux-6.15/drivers/video/fbdev/core/Kconfig