On Mon, Jul 27, 2026 at 11:49 PM YoungJoon Lee <[email protected]> wrote: > > Hello, > > I tested patches 1/5 through 5/5 from the MT8173 PowerVR v3 series on > an Acer Chromebook R13 (Google Elm), which uses an MT8173 SoC and a > PowerVR Rogue GX6250 GPU with BVNC 4.40.2.51. > > For clarity, I applied the five actual patches numbered 1/5 through > 5/5. The 0/5 cover letter itself was not applied. > > Kernel: > Linux 7.1.3-stb-cbm-pvr-v3
Please at least try linux-next. There's around 30 patches for powervr between v7.1 and next-20260727, 15 if you count from v7.1 to v7.2-rc1. > Relevant kernel configuration: > CONFIG_DRM_POWERVR=m > CONFIG_COMMON_CLK_MT8173_MFGTOP=y > > Kernel command line: > powervr.exp_hw_support=1 > > Firmware: > powervr/rogue_4.40.2.51_v1.fw > > The driver probes successfully, loads the firmware, and initializes the > DRM device: > > [ 6.110569] powervr 13000000.gpu: > [drm] Running on unknown hardware; expect issues. > [ 6.117454] powervr 13000000.gpu: > [drm] loaded firmware > powervr/rogue_4.40.2.51_v1.fw > [ 6.118010] powervr 13000000.gpu: > [drm] FW version v1.0 (build 6476056 OS) > [ 6.122992] [drm] Initialized powervr 1.0.0 > for 13000000.gpu on minor 1 > > The following DRM device nodes are created: > > /dev/dri/card0 > /dev/dri/card1 > /dev/dri/renderD128 > > However, on a clean boot, without manually running vulkaninfo, vkcube, > or another Vulkan application, the driver reports that the GPU has been > lost approximately six seconds after DRM initialization: > > [ 12.084078] powervr 13000000.gpu: > [drm] *ERROR* GPU device lost > > The relevant boot sequence is therefore: > > [ 6.110569] PowerVR probe begins > [ 6.117454] Firmware is loaded > [ 6.118010] Firmware version is reported > [ 6.122992] DRM initialization completes > [ 12.084078] GPU device lost > > The unused-regulator shutdown occurs considerably later: > > [ 31.712124] vgpu: disabling > > Therefore, the later "vgpu: disabling" message does not appear to be > the immediate cause of the device loss. The GPU is reported lost about > 20 seconds before that regulator shutdown message. > > After the failure, regulator_summary reports: > > vgpu 0 0 0 normal 1000mV 0mA 700mV 1350mV This is unrelated. This regulator output is _really_ unused. "vgpu" is just the default name on the PMIC. > This output was collected after the GPU had already been reported lost, > so I do not know whether the regulator state was different during probe > or immediately before the failure. > > The PowerVR-related clocks appear enabled in clk_summary: > > mfg_26m 26000000 Hz > > mem_mfg_in_sel > rate: 455000000 Hz > enable: 1 > prepare: 1 > > mfg_mem > rate: 455000000 Hz > enable: 1 > prepare: 1 > consumer: 13000000.gpu > clock name: mem > > mfg_sel > rate: 455000000 Hz > enable: 1 > prepare: 1 > > mfg_g3d > rate: 455000000 Hz > enable: 1 > prepare: 1 > consumer: 13000000.gpu > clock name: core > > axi_mfg_in_sel > rate: 208000000 Hz > enable: 2 > prepare: 2 > consumer: power-domain@7 > > mfg_axi > rate: 208000000 Hz > enable: 1 > prepare: 1 > consumer: 13000000.gpu > clock name: sys > > I also installed Mesa 26.1.5 and vulkan-powervr 26.1.5 and tested the > Vulkan ICD with: > > PVR_I_WANT_A_BROKEN_VULKAN_DRIVER=1 \ > VK_DRIVER_FILES=/usr/share/vulkan/icd.d/powervr_mesa_icd.json \ > vulkaninfo --summary > > The PowerVR ICD was found and loaded. Before hanging, Mesa printed: > > WARNING: powervr is not a conformant Vulkan implementation, > testing use only. > > FINISHME: Missing reset support for brn51764 > FINISHME: Missing reset support for brn58839 > FINISHME: Missing support for brn62269 > FINISHME: Devices without tpu_border_colour_enhanced require entries > for compressed formats to be stored in the table > pre-compressed. > > The vulkaninfo process then remained in uninterruptible sleep: > > PID STAT WCHAN COMMAND > 3244 Dl+ synchronize_srcu vulkaninfo --summary > > It could not be terminated normally while in that state, and a reboot > was required. > > However, the clean-boot log shows that "GPU device lost" occurs even > without starting vulkaninfo manually. The vulkaninfo hang may therefore > be a consequence of the GPU already being in the lost state, rather than > the original cause of the failure. > > At this point, the following parts appear to work: > > - MT8173 GPU device-tree node probing > - MFGTOP clock registration > - PowerVR kernel module probing > - Firmware loading > - Firmware version reporting > - DRM device initialization > - Creation of card1 and renderD128 > > The remaining problem is that the GPU becomes lost approximately six > seconds after initialization. Sorry. I'm not seeing this on my device. I'm running the patches on top of next-20260727 this round. ChenYu > Could this be related to an interrupt not being delivered, firmware > heartbeat handling, reset sequencing, runtime PM, a missing regulator > consumer relationship, or another MT8173-specific power-domain > requirement? > > Please let me know which additional kernel debug options, DRM debug > settings, tracepoints, interrupt statistics, register dumps, or test > patches would be useful. I have physical access to the device and can > build and test further kernel changes. > > Thank you for working on MT8173 support. > > Best regards, > YoungJoon Lee > > 2026年7月27日(月) 18:16 Chen-Yu Tsai <[email protected]>: > > > > Hi everyone, > > > > This is v3 of my MT8173 PowerVR GPU support series. > > > > I got another inquiry on the status of this patch series, so I thought > > I'd dig it out, fix all the issues and send another version. > > > > This time around Mesa was ready for basic testing, using both vulkanmark > > and glmark2-es2-drm (with Zink). Details below. > > > > Changes since v2 (all in the clk driver patch): > > - Made COMMON_CLK_MT8173_MFGTOP depend on PM > > - Needed since the driver implements PM domains using the generic PM > > domain library, which also depends on PM > > - Fixes build breakage (kernel test robot) > > - Fixed "RST_DELAY_CNT" name (Brian) > > - Dropped unused mfg_desc (Brian) > > - Added check of clk_prepare_enable()'s return value in > > clk_mt8173_mfgtop_power_on() (Brian) > > - Saved error value for return in IS_ERR(data->clk_26m) branch > > (Dan Carpenter / kernel test robot w/ smatch) > > > > Changes since v1: > > - Adapted to changed DT bindings > > - Dropped driver change > > - Use same power domain for "a" and "b" GPU power domains > > > > > > This series enables the PowerVR GPU found in the MT8173 SoC, found in > > some Chromebooks. > > > > This version is different from the initial powervr driver submission [1] > > in that it splits out the GPU glue layer support out of the powervr > > driver and into a separate clock and power domain driver. The glue code > > is otherwise the same, and also the same as found in the ChromeOS > > kernels, with some extra comments and macro names added where possible. > > > > Patch 1 adds a binding for the glue layer, called mfgtop. The glue layer > > contains clock and power controls for the GPU. > > > > Patch 2 adds a driver for the glue layer, implemented as a clock driver > > that also provides power domains. > > > > Patch 3 adds an entry for the MT8173 GPU and 6XT series to the PowerVR > > binding. > > > > Patch 4 corrects the clock for the GPU (called MFG) power domain. > > > > Patch 5 adds device nodes for the GPU and glue layer to the MT8173 dtsi > > file. > > > > The kernel driver successfully probes the hardware and loads the > > "rogue_4.40.2.51_v1.fw" firmware provided by Imagination Technologies [2]. > > The "exp_hw_support" module parameter needs to be set for the driver to > > probe successfully. > > > > This was tested with Mesa 26.1.5 from Debian Forky. With this version > > vkmark and glmark2-es2 (over Zink) both run fine. Mesa spits out a bunch > > of warnings since the GX6250 core is not officially supported. > > > > # PVR_I_WANT_A_BROKEN_VULKAN_DRIVER=1 vkmark > > WARNING: powervr is not a conformant Vulkan implementation, testing use > > only. > > WARNING: powervr is not a conformant Vulkan implementation, testing use > > only. > > MESA: warning: ../src/imagination/vulkan/pvr_arch_job_context.c:73: > > FINISHME: Missing reset support for brn51764 > > MESA: warning: ../src/imagination/vulkan/pvr_arch_job_context.c:76: > > FINISHME: Missing reset support for brn58839 > > MESA: warning: ../src/imagination/vulkan/pvr_arch_job_context.c:523: > > FINISHME: Missing support for brn62269 > > MESA: warning: ../src/imagination/vulkan/pvr_arch_border.c:244: > > FINISHME: Devices without tpu_border_colour_enhanced require entries for > > compressed formats to be stored in the table pre-compressed. > > WARNING: powervr is not a conformant Vulkan implementation, testing use > > only. > > ======================================================= > > vkmark 2025.01 > > ======================================================= > > Vendor ID: 0x1010 > > Device ID: 0x6250 > > Device Name: PowerVR Rogue GX6250 > > Driver Version: 109056005 > > Device UUID: d04cd6f3a25fd4900f89c151bccfdfcf > > ======================================================= > > [vertex] device-local=true: FPS: 251 FrameTime: 3.984 ms > > [vertex] device-local=false: FPS: 220 FrameTime: 4.545 ms > > [texture] anisotropy=0:^C FPS: 223 FrameTime: 4.484 ms > > ======================================================= > > vkmark Score: 231 > > ======================================================= > > > > # PVR_I_WANT_A_BROKEN_VULKAN_DRIVER=1 glmark2-es2-drm > > WARNING: powervr is not a conformant Vulkan implementation, testing use > > only. > > MESA: warning: ../src/imagination/vulkan/pvr_arch_job_context.c:73: > > FINISHME: Missing reset support for brn51764 > > MESA: warning: ../src/imagination/vulkan/pvr_arch_job_context.c:76: > > FINISHME: Missing reset support for brn58839 > > MESA: warning: ../src/imagination/vulkan/pvr_arch_job_context.c:523: > > FINISHME: Missing support for brn62269 > > MESA: warning: ../src/imagination/vulkan/pvr_arch_border.c:244: > > FINISHME: Devices without tpu_border_colour_enhanced require entries for > > compressed formats to be stored in the table pre-compressed. > > Warning: DRM_CAP_ASYNC_PAGE_FLIP not supported, falling back to > > 'mailbox' mode for SwapInterval(0). > > ======================================================= > > glmark2 2023.01 > > ======================================================= > > OpenGL Information > > GL_VENDOR: Mesa > > GL_RENDERER: zink Vulkan 1.2(PowerVR Rogue GX6250 > > (IMAGINATION_OPEN_SOURCE_MESA)) > > GL_VERSION: OpenGL ES 2.0 Mesa 26.1.5-1 > > Surface Config: buf=32 r=8 g=8 b=8 a=8 depth=24 stencil=0 samples=0 > > Surface Size: 1366x768 fullscreen > > ======================================================= > > [build] use-vbo=false: FPS: 49 FrameTime: 20.473 ms > > [build] use-vbo=true: FPS: 45 FrameTime: 22.660 ms > > [texture] texture-filter=nearest: FPS: 45 FrameTime: 22.642 ms > > [texture] texture-filter=linear:^C FPS: 50 FrameTime: 20.172 ms > > ======================================================= > > glmark2 Score: 46 > > ======================================================= > > > > > > Please have a look. > > > > Thanks > > ChenYu > > > > [1] > > https://lore.kernel.org/dri-devel/[email protected]/ > > [2] https://gitlab.freedesktop.org/imagination/linux-firmware/-/tree/powervr > > > > Chen-Yu Tsai (5): > > dt-bindings: clock: mediatek: Add mt8173 mfgtop > > clk: mediatek: Add mt8173-mfgtop driver > > dt-bindings: gpu: powervr-rogue: Add MediaTek MT8173 GPU > > arm64: dts: mediatek: mt8173: Fix MFG_ASYNC power domain clock > > arm64: dts: mediatek: mt8173: Add GPU device nodes > > > > .../clock/mediatek,mt8173-mfgtop.yaml | 70 +++++ > > .../bindings/gpu/img,powervr-rogue.yaml | 1 + > > arch/arm64/boot/dts/mediatek/mt8173.dtsi | 33 ++- > > drivers/clk/mediatek/Kconfig | 10 + > > drivers/clk/mediatek/Makefile | 1 + > > drivers/clk/mediatek/clk-mt8173-mfgtop.c | 241 ++++++++++++++++++ > > include/dt-bindings/clock/mt8173-clk.h | 7 + > > 7 files changed, 362 insertions(+), 1 deletion(-) > > create mode 100644 > > Documentation/devicetree/bindings/clock/mediatek,mt8173-mfgtop.yaml > > create mode 100644 drivers/clk/mediatek/clk-mt8173-mfgtop.c > > > > -- > > 2.55.0.229.g6434b31f56-goog > >
