kernel/linux.git/drivers/gpu/drm/mgag200, branch v6.1.168

drm/mgag200: fix mgag200_bmc_stop_scanout()

2026-02-11T12:37:25+00:00

[ Upstream commit 0e0c8f4d16de92520623aa1ea485cadbf64e6929 ] The mgag200_bmc_stop_scanout() function is called by the .atomic_disable() handler for the MGA G200 VGA BMC encoder. This function performs a few register writes to inform the BMC of an upcoming mode change, and then polls to wait until the BMC actually stops. The polling is implemented using a busy loop with udelay() and an iteration timeout of 300, resulting in the function blocking for 300 milliseconds. The function gets called ultimately by the output_poll_execute work thread for the DRM output change polling thread of the mgag200 driver: kworker/0:0-mm_ 3528 [000] 4555.315364: ffffffffaa0e25b3 delay_halt.part.0+0x33 ffffffffc03f6188 mgag200_bmc_stop_scanout+0x178 ffffffffc087ae7a disable_outputs+0x12a ffffffffc087c12a drm_atomic_helper_commit_tail+0x1a ffffffffc03fa7b6 mgag200_mode_config_helper_atomic_commit_tail+0x26 ffffffffc087c9c1 commit_tail+0x91 ffffffffc087d51b drm_atomic_helper_commit+0x11b ffffffffc0509694 drm_atomic_commit+0xa4 ffffffffc05105e8 drm_client_modeset_commit_atomic+0x1e8 ffffffffc0510ce6 drm_client_modeset_commit_locked+0x56 ffffffffc0510e24 drm_client_modeset_commit+0x24 ffffffffc088a743 __drm_fb_helper_restore_fbdev_mode_unlocked+0x93 ffffffffc088a683 drm_fb_helper_hotplug_event+0xe3 ffffffffc050f8aa drm_client_dev_hotplug+0x9a ffffffffc088555a output_poll_execute+0x29a ffffffffa9b35924 process_one_work+0x194 ffffffffa9b364ee worker_thread+0x2fe ffffffffa9b3ecad kthread+0xdd ffffffffa9a08549 ret_from_fork+0x29 On a server running ptp4l with the mgag200 driver loaded, we found that ptp4l would sometimes get blocked from execution because of this busy waiting loop. Every so often, approximately once every 20 minutes -- though with large variance -- the output_poll_execute() thread would detect some sort of change that required performing a hotplug event which results in attempting to stop the BMC scanout, resulting in a 300msec delay on one CPU. On this system, ptp4l was pinned to a single CPU. When the output_poll_execute() thread ran on that CPU, it blocked ptp4l from executing for its 300 millisecond duration. This resulted in PTP service disruptions such as failure to send a SYNC message on time, failure to handle ANNOUNCE messages on time, and clock check warnings from the application. All of this despite the application being configured with FIFO_RT and a higher priority than the background workqueue tasks. (However, note that the kernel did not use CONFIG_PREEMPT...) It is unclear if the event is due to a faulty VGA connection, another bug, or actual events causing a change in the connection. At least on the system under test it is not a one-time event and consistently causes disruption to the time sensitive applications. The function has some helpful comments explaining what steps it is attempting to take. In particular, step 3a and 3b are explained as such: 3a - The third step is to verify if there is an active scan. We are waiting on a 0 on remhsyncsts (. 3b - This step occurs only if the remove is actually scanning. We are waiting for the end of the frame which is a 1 on remvsyncsts (). The actual steps 3a and 3b are implemented as while loops with a non-sleeping udelay(). The first step iterates while the tmp value at position 0 is *not* set. That is, it keeps iterating as long as the bit is zero. If the bit is already 0 (because there is no active scan), it will iterate the entire 300 attempts which wastes 300 milliseconds in total. This is opposite of what the description claims. The step 3b logic only executes if we do not iterate over the entire 300 attempts in the first loop. If it does trigger, it is trying to check and wait for a 1 on the remvsyncsts. However, again the condition is actually inverted and it will loop as long as the bit is 1, stopping once it hits zero (rather than the explained attempt to wait until we see a 1). Worse, both loops are implemented using non-sleeping waits which spin instead of allowing the scheduler to run other processes. If the kernel is not configured to allow arbitrary preemption, it will waste valuable CPU time doing nothing. There does not appear to be any documentation for the BMC register interface, beyond what is in the comments here. It seems more probable that the comment here is correct and the implementation accidentally got inverted from the intended logic. Reading through other DRM driver implementations, it does not appear that the .atomic_enable or .atomic_disable handlers need to delay instead of sleep. For example, the ast_astdp_encoder_helper_atomic_disable() function calls ast_dp_set_phy_sleep() which uses msleep(). The "atomic" in the name is referring to the atomic modesetting support, which is the support to enable atomic configuration from userspace, and not to the "atomic context" of the kernel. There is no reason to use udelay() here if a sleep would be sufficient. Replace the while loops with a read_poll_timeout() based implementation that will sleep between iterations, and which stops polling once the condition is met (instead of looping as long as the condition is met). This aligns with the commented behavior and avoids blocking on the CPU while doing nothing. Note the RREG_DAC is implemented using a statement expression to allow working properly with the read_poll_timeout family of functions. The other RREG_ macros ought to be cleaned up to have better semantics, and several places in the mgag200 driver could make use of RREG_DAC or similar RREG_* macros should likely be cleaned up for better semantics as well, but that task has been left as a future cleanup for a non-bugfix. Fixes: 414c45310625 ("mgag200: initial g200se driver (v2)") Suggested-by: Thomas Zimmermann Signed-off-by: Jacob Keller Reviewed-by: Thomas Zimmermann Reviewed-by: Jocelyn Falempe Signed-off-by: Thomas Zimmermann Link: https://patch.msgid.link/20260202-jk-mgag200-fix-bad-udelay-v2-1-ce1e9665987d@intel.com Signed-off-by: Sasha Levin

drm/mgag200: Fix big-endian support

2026-01-11T14:19:12+00:00

commit 6cb31fba137d45e682ce455b8ea364f44d5d4f98 upstream. Unlike the original, deleted Matrox mga driver, the new mgag200 driver has the XRGB frame-buffer byte swapped on big-endian "RISC" systems. Fix by enabling byte swapping "PowerPC" OPMODE for any __BIG_ENDIAN config. Fixes: 414c45310625 ("mgag200: initial g200se driver (v2)") Signed-off-by: René Rebe Cc: stable@kernel.org Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://patch.msgid.link/20251208.141827.965103015954471168.rene@exactco.de Signed-off-by: Greg Kroah-Hartman

drm/mgag200: Bind I2C lifetime to DRM device

2024-08-14T11:53:00+00:00

commit eb1ae34e48a09b7a1179c579aed042b032e408f4 upstream. Managed cleanup with devm_add_action_or_reset() will release the I2C adapter when the underlying Linux device goes away. But the connector still refers to it, so this cleanup leaves behind a stale pointer in struct drm_connector.ddc. Bind the lifetime of the I2C adapter to the connector's lifetime by using DRM's managed release. When the DRM device goes away (after the Linux device) DRM will first clean up the connector and then clean up the I2C adapter. Signed-off-by: Thomas Zimmermann Reviewed-by: Jocelyn Falempe Fixes: b279df242972 ("drm/mgag200: Switch I2C code to managed cleanup") Cc: Thomas Zimmermann Cc: Jocelyn Falempe Cc: Dave Airlie Cc: dri-devel@lists.freedesktop.org Cc: # v6.0+ Link: https://patchwork.freedesktop.org/patch/msgid/20240513125620.6337-3-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman

drm/mgag200: Set DDC timeout in milliseconds

2024-08-14T11:53:00+00:00

commit ecde5db1598aecab54cc392282c15114f526f05f upstream. Compute the i2c timeout in jiffies from a value in milliseconds. The original values of 2 jiffies equals 2 milliseconds if HZ has been configured to a value of 1000. This corresponds to 2.2 milliseconds used by most other DRM drivers. Update mgag200 accordingly. Signed-off-by: Thomas Zimmermann Reviewed-by: Jocelyn Falempe Fixes: 414c45310625 ("mgag200: initial g200se driver (v2)") Cc: Dave Airlie Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: Jocelyn Falempe Cc: dri-devel@lists.freedesktop.org Cc: # v3.5+ Link: https://patchwork.freedesktop.org/patch/msgid/20240513125620.6337-2-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman

drm/mgag200: Fix gamma lut not initialized for G200ER, G200EV, G200SE

2024-01-10T16:10:21+00:00

commit 11f9eb899ecc8c02b769cf8d2532ba12786a7af7 upstream. When mgag200 switched from simple KMS to regular atomic helpers, the initialization of the gamma settings was lost. This leads to a black screen, if the bios/uefi doesn't use the same pixel color depth. This has been fixed with commit ad81e23426a6 ("drm/mgag200: Fix gamma lut not initialized.") for most G200, but G200ER, G200EV, G200SE use their own version of crtc_helper_atomic_enable() and need to be fixed too. Fixes: 1baf9127c482 ("drm/mgag200: Replace simple-KMS with regular atomic helpers") Cc: #v6.1+ Reported-by: Roger Sewell Suggested-by: Roger Sewell Signed-off-by: Jocelyn Falempe Reviewed-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20231214163849.359691-1-jfalempe@redhat.com Signed-off-by: Greg Kroah-Hartman

drm/mgag200: Fix gamma lut not initialized.

2023-05-30T13:03:19+00:00

commit ad81e23426a651eb89a4b306e1c4169e6308c124 upstream. When mgag200 switched from simple KMS to regular atomic helpers, the initialization of the gamma settings was lost. This leads to a black screen, if the bios/uefi doesn't use the same pixel color depth. v2: rebase on top of drm-misc-fixes, and add Cc stable tag. Link: https://bugzilla.redhat.com/show_bug.cgi?id=2171155 Fixes: 1baf9127c482 ("drm/mgag200: Replace simple-KMS with regular atomic helpers") Cc: Tested-by: Phil Oester Reviewed-by: Thomas Zimmermann Signed-off-by: Jocelyn Falempe Link: https://patchwork.freedesktop.org/patch/msgid/20230510131034.284078-1-jfalempe@redhat.com Signed-off-by: Greg Kroah-Hartman

drm/mgag200: Fix PLL setup for G200_SE_A rev >=4

2023-01-07T10:11:57+00:00

commit b389286d0234e1edbaf62ed8bc0892a568c33662 upstream. For G200_SE_A, PLL M setting is wrong, which leads to blank screen, or "signal out of range" on VGA display. previous code had "m |= 0x80" which was changed to m |= ((pixpllcn & BIT(8)) >> 1); Tested on G200_SE_A rev 42 This line of code was moved to another file with commit 877507bb954e ("drm/mgag200: Provide per-device callbacks for PIXPLLC") but can be easily backported before this commit. v2: * put BIT(7) First to respect MSB-to-LSB (Thomas) * Add a comment to explain that this bit must be set (Thomas) Fixes: 2dd040946ecf ("drm/mgag200: Store values (not bits) in struct mgag200_pll_values") Cc: stable@vger.kernel.org Signed-off-by: Jocelyn Falempe Reviewed-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20221013132810.521945-1-jfalempe@redhat.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'drm-next-2022-10-05' of git://anongit.freedesktop.org/drm/drm

2022-10-05T18:24:12+00:00

Pull drm updates from Dave Airlie: "Lots of stuff all over, some new AMD IP support and gang submit support. i915 has further DG2 and Meteorlake pieces, and a bunch of i915 display refactoring. msm has a shrinker rework. There are also a bunch of conversions to use kunit. This has two external pieces, some MEI changes needed for future Intel discrete GPUs. These should be acked by Greg. There is also a cross maintainer shared tree with some backlight rework from Hans in here. Core: - convert selftests to kunit - managed init for more objects - move to idr_init_base - rename fb and gem cma helpers to dma - hide unregistered connectors from getconnector ioctl - DSC passthrough aux support - backlight handling improvements - add dma_resv_assert_held to vmap/vunmap edid: - move luminance calculation to core fbdev: - fix aperture helper usage fourcc: - add more format helpers - add DRM_FORMAT_Cxx, DRM_FORMAT_Rxx, DRM_FORMAT_Dxx - add packed AYUV8888, XYUV8888 - add some kunit tests ttm: - allow bos without backing store - rewrite placement to use intersect/compatible functions dma-buf: - docs update - improve signalling when debugging udmabuf: - fix failure path GPF dp: - drop dp/mst legacy code - atomic mst state support - audio infoframe packing panel: - Samsung LTL101AL01 - B120XAN01.0 - R140NWF5 RH - DMT028VGHMCMI-1A T - AUO B133UAN02.1 - IVO M133NW4J-R3 - Innolux N120ACA-EA1 amdgpu: - Gang submit support - Mode2 reset for RDNA2 - New IP support: DCN 3.1.4, 3.2 SMU 13.x NBIO 7.7 GC 11.x PSP 13.x SDMA 6.x GMC 11.x - DSC passthrough support - PSP fixes for TA support - vangogh GFXOFF stats - clang fixes - gang submit CS cleanup prep work - fix VRAM eviction issues amdkfd: - GC 10.3 IP ISA fixes - fix CRIU regression - CPU fault on COW mapping fixes i915: - align fw versioning with kernel practices - add display substruct to i915 private - add initial runtime info to driver info - split out HDCP and backlight registers - MEI XeHP SDV GSC support - add per-gt sysfs defaults - TLB invalidation improvements - Disable PCI BAR resize on 32-bit - GuC firmware updates and compat changes - GuC log timestamp translation - DG2 preemption workaround changes - DG2 improved HDMI pixel clocks support - PCI BAR sanity checks - Enable DC5 on DG2 - DG2 DMC fw bumped - ADL-S PCI ID added - Meteorlake enablement - Rename ggtt_view to gtt_view - host RPS fixes - release mmaps on rpm suspend on discrete - clocking and dpll refactoring - VBT definitions and parsing updates - SKL watermark code extracted to separate file - allow seamless M/N changes on eDP panels - BUG_ON removal and cleanups msm: - DPU: simplified VBIF configuration cleanup CTL interfaces - DSI: removed unused msm_display_dsc_config struct switch regulator calls to new API switched to PANEL_BRIDGE for direct attached panels - DSI_PHY: convert drivers to parent_hws - DP: cleanup pixel_rate handling - HDMI: turned hdmi-phy-8996 into OF clk provider - misc dt-bindings fixes - choose eDP as primary display if it's available - support getting interconnects from either the mdss or the mdp5/dpu device nodes - gem: Shrinker + LRU re-work: - adds a shared GEM LRU+shrinker helper and moves msm over to that - reduce lock contention between retire and submit by avoiding the need to acquire obj lock in retire path (and instead using resv seeing obj's busyness in the shrinker - fix reclaim vs submit issues - GEM fault injection for triggering userspace error paths - Map/unmap optimization - Improved robustness for a6xx GPU recovery virtio: - improve error and edge conditions handling - convert to use managed helpers - stop exposing LINEAR modifier mgag200: - split modeset handling per model udl: - suspend/disconnect handling improvements vc4: - rework HDMI power up - depend on PM - better unplugging support ast: - resolution handling improvements ingenic: - add JZ4760(B) support - avoid a modeset when sharpness property is unchanged - use the new PM ops it6505: - power seq and clock updates ssd130x: - regmap bulk write - use atomic helpers instead of simple helpers via: - rename via_drv to via_dri1, consolidate all code. radeon: - drop DP MST experimental support - delayed work flush fix - use time_after ti-sn65dsi86: - DP support mediatek: - MT8195 DP support - drop of_gpio header - remove unneeded result - small DP code improvements vkms: - RGB565, XRGB64 and ARGB64 support sun4i: - tv: convert to atomic rcar-du: - Synopsys DW HDMI bridge DT bindings update exynos: - use drm_display_info.is_hdmi - correct return of mixer_mode_valid and hdmi_mode_valid omap: - refcounting fix rockchip: - RK3568 support - RK3399 gamma support" * tag 'drm-next-2022-10-05' of git://anongit.freedesktop.org/drm/drm: (1374 commits) drm/amdkfd: Fix UBSAN shift-out-of-bounds warning drm/amdkfd: Track unified memory when switching xnack mode drm/amdgpu: Enable sram on vcn_4_0_2 drm/amdgpu: Enable VCN DPG for GC11_0_1 drm/msm: Fix build break with recent mm tree drm/panel: simple: Use dev_err_probe() to simplify code drm/panel: panel-edp: Use dev_err_probe() to simplify code drm/panel: simple: Add Multi-Inno Technology MI0800FT-9 dt-bindings: display: simple: Add Multi-Inno Technology MI0800FT-9 panel drm/amdgpu: correct the memcpy size for ip discovery firmware drm/amdgpu: Skip put_reset_domain if it doesn't exist drm/amdgpu: remove switch from amdgpu_gmc_noretry_set drm/amdgpu: Fix mc_umc_status used uninitialized warning drm/amd/display: Prevent OTG shutdown during PSR SU drm/amdgpu: add page retirement handling for CPU RAS drm/amdgpu: use RAS error address convert api in mca notifier drm/amdgpu: support to convert dedicated umc mca address drm/amdgpu: export umc error address convert interface drm/amdgpu: fix sdma v4 init microcode error drm/amd/display: fix array-bounds error in dc_stream_remove_writeback() ...

drm/mgag200: Force 32 bpp on the console

2022-09-20T07:20:23+00:00

G200ER does not seem to support 24 bpp, so force the console to use 32 bpp. The problem got introduced when commit 73f54d5d9682 ("drm/mgag200: Remove special case for G200SE with <2 MiB") changed the preferred color depth from 32 bit to 24 bit. A setting of 24 is the correct color depth, but G200ER doesn't seem to be able to use the respective RGB888 color format. Using 24-bit color with forced 32 bpp works around the problem. Reported-by: Wang Yugui Signed-off-by: Thomas Zimmermann Tested-by: Wang Yugui Reviewed-by: Jocelyn Falempe Fixes: 73f54d5d9682 ("drm/mgag200: Remove special case for G200SE with <2 MiB") Cc: Thomas Zimmermann Cc: Jocelyn Falempe Cc: Dave Airlie Cc: dri-devel@lists.freedesktop.org Link: https://patchwork.freedesktop.org/patch/msgid/20220915150348.31504-1-tzimmermann@suse.de

drm/format-helper: Merge drm_fb_memcpy() and drm_fb_memcpy_toio()

2022-08-10T07:15:51+00:00

Merge drm_fb_memcpy() and drm_fb_memcpy_toio() into a drm_fb_memcpy() that uses struct iosys_map for buffers. The new function also supports multi-plane color formats. Convert all users of the original helpers. v2: * rebase onto refactored mgag200 * use drm_formap_info_bpp() (Sam) * do static init in hyperv and mgag200 (Sam) * update documentation (Sam) * add TODO on vaddr location (Sam) Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-4-tzimmermann@suse.de