Re: [PATCH RFC RFT] drm/msm: adreno: attach the GMU device to a driver

[Neil Armstrong <neil.armstrong@linaro.org>]

On 11/4/25 02:30, Jens Reidel wrote:
> Hi Neil,
> 
> On 10/29/25 11:25 AM, Neil Armstrong wrote:
>> Hi,
>>
>> On 10/26/25 02:31, Jens Reidel wrote:
>>> On 10/22/25 14:44, Neil Armstrong wrote:
>>>> Due to the sync_state is enabled by default in pmdomain & CCF since v6.17,
>>>> the GCC and GPUCC sync_state would stay pending, leaving the resources in
>>>> full performance:
>>>> gcc-x1e80100 100000.clock-controller: sync_state() pending due to 3d6a000.gmu
>>>> gpucc-x1e80100 3d90000.clock-controller: sync_state() pending due to 3d6a000.gmu
>>>>
>>>> In order to fix this state and allow the GMU to be properly
>>>> probed, let's add a proper driver for the GMU and add it to
>>>> the MSM driver components.
>>>>
>>>> Only the proper GMU has been tested since I don't have
>>>> access to hardware with a GMU wrapper.
>>>>
>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>> ---
>>>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.c      | 354 +++++++++++++ +---------------
>>>>   drivers/gpu/drm/msm/adreno/a6xx_gpu.c      |   6 -
>>>>   drivers/gpu/drm/msm/adreno/a6xx_gpu.h      |   3 -
>>>>   drivers/gpu/drm/msm/adreno/adreno_device.c |   4 +
>>>>   drivers/gpu/drm/msm/adreno/adreno_gpu.h    |   4 +
>>>>   drivers/gpu/drm/msm/msm_drv.c              |  16 +-
>>>>   6 files changed, 192 insertions(+), 195 deletions(-)
>>>>
>>
>> <snip>
>>
>>>>
>>>> ---
>>>> base-commit: 211ddde0823f1442e4ad052a2f30f050145ccada
>>>> change-id: 20251022-topic-adreno-attach-gmu-to-driver-e47025fd7ebb
>>>>
>>>> Best regards,
>>>
>>> Hi Neil,
>>>
>>> thanks for the patch. With it applied, my GPU fails to initialize.
>>> Here's the related dmesg section:
>>>
>>> [    1.733062] [drm:dpu_kms_hw_init:1173] dpu hardware revision:0x50020000
>>> [    1.735229] [drm] Initialized msm 1.13.0 for ae01000.display- controller on minor 0
>>> [    1.735403] msm_dpu ae01000.display-controller: [drm:adreno_request_fw] loaded qcom/a630_sqe.fw from new location
>>> [    1.735513] msm_dpu ae01000.display-controller: [drm:adreno_request_fw] loaded qcom/a630_gmu.bin from new location
>>> [    1.746710] a6xx_gmu 506a000.gmu: [drm:a6xx_gmu_set_oob] *ERROR* Timeout waiting for GMU OOB set BOOT_SLUMBER: 0x800000
>>> [    1.746766] msm_dpu ae01000.display-controller: [drm:adreno_load_gpu] *ERROR* Couldn't power up the GPU: -110
>>>
>>> This could be because I have an Adreno 630-family GPU, which is marked as legacy in a6xx_gmu_init / a6xx_gmu_bind. Previously, the rest of the init code would just always run, while now, some parts are conditionally disabled for legacy GPUs - that may be unintentional? However, unconditionally enabling those parts seems to fail to initialize the GPU followed by a reset shortly after, so there's probably more to this.
>>>
>>> Please let me know if there's anything I can do to help debug this.
>>
>> Thanks for the report, it's an sdm845 based right ?
> 
> Almost, it's SM7150 with Adreno 618.
> 
>>
>> I may have mismatched the role of the legacy parameter...
>>
>> Could you try this on top:
> 
> <snip>
> 
>> ===========================><=====================================
> 
> This is about what I had already tried earlier. I wasn't able to grab a log from
> UART to see what exactly was still wrong back then, but I finally got around to it today.
> 
> Short excerpt from decoded stacktrace:
> 
> [    4.838573] Unable to handle kernel paging request at virtual address 0000000000023010
> [    4.846726] Mem abort info:
> [    4.857916]   ESR = 0x0000000096000044
> [    4.870865]   EC = 0x25: DABT (current EL), IL = 32 bits
> [    4.883897]   SET = 0, FnV = 0
> [    4.895344]   EA = 0, S1PTW = 0
> [    4.898584]   FSC = 0x04: level 0 translation fault
> [    4.898586] Data abort info:
> [    4.898587]   ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
> [    4.898589]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
> [    4.898591]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [    4.898593] [0000000000023010] user address but active_mm is swapper
> [    4.898597] Internal error: Oops: 0000000096000044 [#1]  SMP
> [    4.898600] Modules linked in:
> [    4.898612] Tainted: [W]=WARN
> [    4.898613] Hardware name: xiaomi Xiaomi POCO X3 NFC (Huaxing)/Xiaomi POCO X3 NFC (Huaxing), BIOS 2025.10-gcb980be18336 10/01/2025
> [    4.898616] Workqueue: events_unbound deferred_probe_work_func
> [    4.911316]
> [    4.911318] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [    4.911321] pc : a6xx_gmu_rpmh_init (arch/arm64/include/asm/io.h:43 include/asm-generic/io.h:293 drivers/gpu/drm/msm/adreno/a6xx_gmu.h:183 drivers/gpu/drm/msm/adreno/a6xx_gmu.c:621)
> [    4.911327] lr : a6xx_gmu_rpmh_init (drivers/gpu/drm/msm/adreno/a6xx_gmu.c:1811)
> [    4.911331] sp : ffff8000809f3560
> [    4.911332] x29: ffff8000809f3560 x28: 0000000000000001
> [    4.919938]  x27: ffff800081e50000
> [    4.919940] x26: 0000000000000300 x25: 0068000000000413 x24: ffffc51d5cca9000
> [    4.919944] x23: 0000000000030090 x22: ffff000080aec3b0 x21: ffff00008162c010
> [    4.919947] x20: ffff000080aec578 x19: ffff800081f90000 x18: 000000000aa663d1
> [    4.919950] x17: ffffc51d5cefc000 x16: ffffc51d5cca9d80 x15: 0078000000000f13
> [    4.930595]
> [    4.930596] x14: 0000000000000000 x13: ffff800081f9ffff x12: ffff800081f9ffff
> [    4.930600] x11: 0000000001000000 x10: 0000000000023010 x9 : 0000000000000000
> [    4.930603] x8 : 0000000000000000 x7 : ffff00008155a960 x6 : 0000000000000000
> [    4.930606] x5 : 0000000000000cc0 x4 : 0000000000001000 x3 : 007800000b49ff13
> [    4.930610] x2 : 000000000b4a0000
> [    4.942943]  x1 : ffff800081fa0000 x0 : ffff800081e50000
> [    4.942947] Call trace:
> [    4.942948]  a6xx_gmu_rpmh_init (arch/arm64/include/asm/io.h:43 include/asm-generic/io.h:293 drivers/gpu/drm/msm/adreno/a6xx_gmu.h:183 drivers/gpu/drm/msm/adreno/a6xx_gmu.c:621) (P)
> [    4.942954]  a6xx_gmu_bind (drivers/gpu/drm/msm/adreno/a6xx_gmu.c:2102)
> [    4.942957]  component_bind_all (drivers/base/component.c:660)
> [    4.956709]  msm_drm_init (drivers/gpu/drm/msm/msm_drv.c:159)
> [    4.956714]  msm_drm_bind (drivers/gpu/drm/msm/msm_drv.c:1032)
> 
> Turns out that previously, gmu->mmio was assigned before setting
> gmu->rscc = gmu->mmio + 0x23000;
> With your changes, the order is now wrong.

Oh crap

> Moving the assignment up again (and applying the diff you shared
> for proper handling of legacy parameter) fixes it:
> 
> ==========================================
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -2027,6 +2027,13 @@ static int a6xx_gmu_bind(struct device *dev, struct device *master, void *data)
>                  if (ret)
>                          goto err_memory;
> 
> +               /* Map the GMU registers */
> +               gmu->mmio = a6xx_gmu_get_mmio(pdev, "gmu");
> +               if (IS_ERR(gmu->mmio)) {
> +                       ret = PTR_ERR(gmu->mmio);
> +                       goto err_memory;
> +               }
> +
>                  if (adreno_is_a650_family(adreno_gpu) ||
>                      adreno_is_a7xx(adreno_gpu)) {
>                          gmu->rscc = a6xx_gmu_get_mmio(pdev, "rscc");
> @@ -2048,13 +2055,6 @@ static int a6xx_gmu_bind(struct device *dev, struct device *master, void *data)
>                  }
>          }
> 
> -       /* Map the GMU registers */
> -       gmu->mmio = a6xx_gmu_get_mmio(pdev, "gmu");
> -       if (IS_ERR(gmu->mmio)) {
> -               ret = PTR_ERR(gmu->mmio);
> -               goto err_memory;
> -       }
> -
>          gmu->cxpd = dev_pm_domain_attach_by_name(gmu->dev, "cx");
>          if (IS_ERR(gmu->cxpd)) {
>                  ret = PTR_ERR(gmu->cxpd);
> ==========================================
> 
> This almost certainly isn't correct either because the wrapper needs
> its registers mapped too, perhaps this is better suited for moving it
> above the if block, I think that makes more sense.

Yes, merging both functions was a bad move...

> 
> With the legacy parameter changes and GMU register mapping prior to RSCC
> offset calculation:Tested-by: Jens Reidel <adrian@mainlining.org> # SM7150

Thanks for testing !

Following Akhil's review, I'll probably keep the wrapper and normal
gmu bind/unbind separated for the first step.

Neil

> 
> Best regards,Jens
>>
>> Thanks,
>> Neil
>>
>>>
>>> Best regards,
>>> Jens
>>