kernel/linux.git/Documentation/gpu, branch v5.10.257

Revert "fbcon: Disable accelerated scrolling"

2022-02-08T17:30:40+00:00

commit 87ab9f6b7417349aa197a6c7098d4fdd4beebb74 upstream. This reverts commit 39aead8373b3c20bb5965c024dfb51a94e526151. Revert the first (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omapdrm and gma500) used hardware acceleration in the past and thus code for checking and using scrolling acceleration is obsolete.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 # v5.10+ Signed-off-by: Helge Deller Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-3-deller@gmx.de Signed-off-by: Greg Kroah-Hartman

drm: Use USB controller's DMA mask when importing dmabufs

2021-03-17T16:06:19+00:00

commit 659ab7a49cbebe0deffcbe1f9560e82006b21817 upstream. USB devices cannot perform DMA and hence have no dma_mask set in their device structure. Therefore importing dmabuf into a USB-based driver fails, which breaks joining and mirroring of display in X11. For USB devices, pick the associated USB controller as attachment device. This allows the DRM import helpers to perform the DMA setup. If the DMA controller does not support DMA transfers, we're out of luck and cannot import. Our current USB-based DRM drivers don't use DMA, so the actual DMA device is not important. Tested by joining/mirroring displays of udl and radeon under Gnome/X11. v8: * release dmadev if device initialization fails (Noralf) * fix commit description (Noralf) v7: * fix use-before-init bug in gm12u320 (Dan) v6: * implement workaround in DRM drivers and hold reference to DMA device while USB device is in use * remove dev_is_usb() (Greg) * collapse USB helper into usb_intf_get_dma_device() (Alan) * integrate Daniel's TODO statement (Daniel) * fix typos (Greg) v5: * provide a helper for USB interfaces (Alan) * add FIXME item to documentation and TODO list (Daniel) v4: * implement workaround with USB helper functions (Greg) * use struct usb_device->bus->sysdev as DMA device (Takashi) v3: * drop gem_create_object * use DMA mask of USB controller, if any (Daniel, Christian, Noralf) v2: * move fix to importer side (Christian, Daniel) * update SHMEM and CMA helpers for new PRIME callbacks Signed-off-by: Thomas Zimmermann Fixes: 6eb0233ec2d0 ("usb: don't inherity DMA properties for USB devices") Tested-by: Pavel Machek Reviewed-by: Greg Kroah-Hartman Acked-by: Christian König Acked-by: Daniel Vetter Acked-by: Noralf Trønnes Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: # v5.10+ Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20210303133229.3288-1-tzimmermann@suse.de Signed-off-by: Maarten Lankhorst Signed-off-by: Greg Kroah-Hartman

fbcon: Disable accelerated scrolling

2021-01-06T13:56:51+00:00

commit 39aead8373b3c20bb5965c024dfb51a94e526151 upstream. So ever since syzbot discovered fbcon, we have solid proof that it's full of bugs. And often the solution is to just delete code and remove features, e.g. 50145474f6ef ("fbcon: remove soft scrollback code"). Now the problem is that most modern-ish drivers really only treat fbcon as an dumb kernel console until userspace takes over, and Oops printer for some emergencies. Looking at drm drivers and the basic vesa/efi fbdev drivers shows that only 3 drivers support any kind of acceleration: - nouveau, seems to be enabled by default - omapdrm, when a DMM remapper exists using remapper rewriting for y/xpanning - gma500, but that is getting deleted now for the GTT remapper trick, and the accelerated copyarea never set the FBINFO_HWACCEL_COPYAREA flag, so unused (and could be deleted already I think). No other driver supportes accelerated fbcon. And fbcon is the only user of this accel code (it's not exposed as uapi through ioctls), which means we could garbage collect fairly enormous amounts of code if we kill this. Plus because syzbot only runs on virtual hardware, and none of the drivers for that have acceleration, we'd remove a huge gap in testing. And there's no other even remotely comprehensive testing aside from syzbot. This patch here just disables the acceleration code by always redrawing when scrolling. The plan is that once this has been merged for well over a year in released kernels, we can start to go around and delete a lot of code. v2: - Drop a few more unused local variables, somehow I missed the compiler warnings (Sam) - Fix typo in comment (Jiri) - add a todo entry for the cleanup (Thomas) v3: Remove more unused variables (0day) Reviewed-by: Tomi Valkeinen Reviewed-by: Thomas Zimmermann Reviewed-by: Greg Kroah-Hartman Acked-by: Sam Ravnborg Cc: Jiri Slaby Cc: Bartlomiej Zolnierkiewicz Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Ben Skeggs Cc: nouveau@lists.freedesktop.org Cc: Tomi Valkeinen Cc: Daniel Vetter Cc: Jiri Slaby Cc: "Gustavo A. R. Silva" Cc: Tetsuo Handa Cc: Peilin Ye Cc: George Kennedy Cc: Nathan Chancellor Cc: Peter Rosin Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20201029132229.4068359-1-daniel.vetter@ffwll.ch Signed-off-by: Greg Kroah-Hartman

gpu: docs: amdgpu.rst: get rid of wrong kernel-doc markups

2020-10-28T17:42:02+00:00

As reported by kernel-doc: ./drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c:1: warning: no structured comments found ./drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c:1: warning: no structured comments found Those files only contain /** * DOC: */ markups, but they're included twice there: one to parse such markup, and another one to parse internal functions. In the case of amdgpu_xgmi.c, as it has just one such markup, we can simply include the file once, and let it parse the entire file without passing arguments to kernel-doc. This should place everything altogether. For amdgpu_ras.c, however, we need to remove the kernel-doc with just internal. This should be re-introduced if this file ever gets new non-DOC markups. Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/bd070923591ae54f9587e7407b6291ac116952b2.1603791716.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

Merge tag 'drm-next-2020-10-19' of git://anongit.freedesktop.org/drm/drm

2020-10-20T17:19:02+00:00

Pull drm fixes from Dave Airlie: "Some fixes queued up already for i915 and amdgpu, I've also included the fix for the clang warning you've seen. i915: - set all unused color plane offsets to ~0xfff again (Ville) - fix TGL DKL PHY DP vswing handling (Ville) amdgpu: - DCN clang warning fix - eDP fix - BACO fix - kernel documentation fixes - SMU7 mclk fix - VCN1 hw bug workaround amdkfd: - kvfree vs kfree fix" * tag 'drm-next-2020-10-19' of git://anongit.freedesktop.org/drm/drm: drm/amd/display: Fix incorrect dsc force enable logic drm/amdkfd: Use kvfree in destroy_crat_image drm/amdgpu: vcn and jpeg ring synchronization drm/amd/pm: increase mclk switch threshold to 200 us docs: amdgpu: fix a warning when building the documentation drm/amd/display: kernel-doc: document force_timing_sync drm/amdgpu/swsmu: init the baco mutex in early_init drm/amd/display: Fix module load hangs when connected to an eDP drm/i915: Set all unused color plane offsets to ~0xfff again drm/i915: Fix TGL DKL PHY DP vswing handling

Merge tag 'docs/v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

2020-10-16T22:02:21+00:00

Pull documentation updates from Mauro Carvalho Chehab: "A series of patches addressing warnings produced by make htmldocs. This includes: - kernel-doc markup fixes - ReST fixes - Updates at the build system in order to support newer versions of the docs build toolchain (Sphinx) After this series, the number of html build warnings should reduce significantly, and building with Sphinx 3.1 or later should now be supported (although it is still recommended to use Sphinx 2.4.4). As agreed with Jon, I should be sending you a late pull request by the end of the merge window addressing remaining issues with docs build, as there are a number of warning fixes that depends on pull requests that should be happening along the merge window. The end goal is to have a clean htmldocs build on Kernel 5.10. PS. It should be noticed that Sphinx 3.0 is not currently supported, as it lacks support for C domain namespaces. Such feature, needed in order to document uAPI system calls with Sphinx 3.x, was added only on Sphinx 3.1" * tag 'docs/v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (75 commits) PM / devfreq: remove a duplicated kernel-doc markup mm/doc: fix a literal block markup workqueue: fix a kernel-doc warning docs: virt: user_mode_linux_howto_v2.rst: fix a literal block markup Input: sparse-keymap: add a description for @sw rcu/tree: docs: document bkvcache new members at struct kfree_rcu_cpu nl80211: docs: add a description for s1g_cap parameter usb: docs: document altmode register/unregister functions kunit: test.h: fix a bad kernel-doc markup drivers: core: fix kernel-doc markup for dev_err_probe() docs: bio: fix a kerneldoc markup kunit: test.h: solve kernel-doc warnings block: bio: fix a warning at the kernel-doc markups docs: powerpc: syscall64-abi.rst: fix a malformed table drivers: net: hamradio: fix document location net: appletalk: Kconfig: Fix docs location dt-bindings: fix references to files converted to yaml memblock: get rid of a :c:type leftover math64.h: kernel-docs: Convert some markups into normal comments media: uAPI: buffer.rst: remove a left-over documentation ...

docs: gpu: i915.rst: Fix several C duplication warnings

2020-10-15T05:49:44+00:00

As reported by Sphinx: ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:1147: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_oa_wait_unlocked'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:1169: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_oa_poll_wait'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:1189: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_oa_read'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:2669: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_oa_stream_enable'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:2734: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_oa_stream_disable'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:2820: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_oa_stream_init'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3010: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_read'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3098: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_poll_locked'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3129: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_poll'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3152: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_enable_locked'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3181: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_disable_locked'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3273: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_ioctl'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3296: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_destroy_locked'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3321: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_release'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3379: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_open_ioctl_locked'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3534: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'read_properties_unlocked'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3717: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_open_ioctl'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3760: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_register'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:3789: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_unregister'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:4009: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_add_config_ioctl'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:4162: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_remove_config_ioctl'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:4260: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_init'. ./Documentation/gpu/i915:646: ./drivers/gpu/drm/i915/i915_perf.c:4423: WARNING: Duplicate C declaration, also defined in 'gpu/i915'. Declaration is 'i915_perf_fini'. With Sphinx 3, C declarations can't be duplicated anymore, so let's exclude those from the other internals found on i915_perf.c file. Signed-off-by: Mauro Carvalho Chehab

docs: amdgpu: fix a warning when building the documentation

2020-10-14T19:26:58+00:00

As reported by Sphinx: Documentation/gpu/amdgpu.rst:200: WARNING: Inline emphasis start-string without end-string. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Alex Deucher

drm/amdgpu: Add initial kernel documentation for the amd_ip_block_type structure. v3

2020-09-22T21:37:38+00:00

Added IP block section to amdgpu.rst. Added more documentation to amd_ip_funcs. Created documentation for amd_ip_block_type. v2: Provides a more detailed DOC section on IP blocks v3: Clarifies the IP block list. Adds info on IP block enumeration. Signed-off-by: Ryan Taylor Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher

Merge tag 'amd-drm-next-5.10-2020-09-03' of git://people.freedesktop.org/~agd5f/linux into drm-next

2020-09-08T06:40:13+00:00

amd-drm-next-5.10-2020-09-03: amdgpu: - RAS fixes - Sienna Cichlid updates - Navy Flounder updates - DCE6 (SI) support in DC - Enable plane rotation - Rework pre-OS vram reservation handling during driver init - Add standard interface to dump GPU metrics table from SMU - Rework tiling and tmz state handling in atomic commits - Pstate fixes - Add voltage and power hwmon interfaces for renoir - SW CTF fixes - S/G display fix for Raven - Print client strings for vmfaults for vega and newer - Manual fan control fixes - Display updates - Reorg power management directory structure - Misc bug fixes - Misc code cleanups amdkfd: - Topology fixes - Add SMI events for thermal throttling and GPU resets radeon: - switch from pci_* to dma_* for dma allocations - PLL fix Scheduler: - Clean up priority levels UAPI: - amdgpu INFO IOCTL query update for TMZ state https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6049 - amdkfd SMI event interface updates https://github.com/RadeonOpenCompute/rocm_smi_lib/tree/therm_thrott From: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20200903222921.4152-1-alexander.deucher@amd.com