Re: [PATCH] iommu/arm-smmu-qcom: Add SM6115 MDSS compatible

["Alexey Klimov" <alexey.klimov@linaro.org>]

On Wed May 28, 2025 at 9:52 AM BST, Dmitry Baryshkov wrote:
> On Wed, May 28, 2025 at 01:31:18AM +0100, Alexey Klimov wrote:
>> Add the SM6115 MDSS compatible to clients compatible list, as it also
>> needs that workaround.
>> Without this workaround, for example, QRB4210 RB2 which is based on
>> SM4250/SM6115 generates a lot of smmu unhandled context faults during
>> boot:
>> 
>> arm_smmu_context_fault: 116854 callbacks suppressed
>> arm-smmu c600000.iommu: Unhandled context fault: fsr=0x402,
>> iova=0x5c0ec600, fsynr=0x320021, cbfrsynra=0x420, cb=5
>> arm-smmu c600000.iommu: FSR    = 00000402 [Format=2 TF], SID=0x420
>> arm-smmu c600000.iommu: FSYNR0 = 00320021 [S1CBNDX=50 PNU PLVL=1]
>> arm-smmu c600000.iommu: Unhandled context fault: fsr=0x402,
>> iova=0x5c0d7800, fsynr=0x320021, cbfrsynra=0x420, cb=5
>> arm-smmu c600000.iommu: FSR    = 00000402 [Format=2 TF], SID=0x420
>> 
>> and also leads to failed initialisation of lontium lt9611uxc driver
>> and gpu afterwards:
>
> Nit: there is nothing failing the lt9611uxc on its own. binding all MDSS
> components (triggered by lt9611uxc attaching to the DSI bus) produces
> the failure.

Oh, I didn't mean to express that something failed in lt9611uxc itself, I
was just trying to list observed problems.
Apart from hdmi bridge and gpu the failed component will be soundcard driver
since it depends on lt9611uxc.. So, if you have rewording in mind feel free
to suggest it.

Or maybe something like this will look better:
and also failed initialisation of lontium lt9611uxc, gpu and dpu is observed:
  (kernel trace as in the original email)

[..]

>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
>
> I'd also propose:
>
> Fixes: 3581b7062cec ("drm/msm/disp/dpu1: add support for display on SM6115")
>
> This way this is going to be fixed for all platforms using display on
> SM6115.

Yes. Thanks. Checkpatch suggested "Fixes" tag but it was unclear when it
started to horribly fail during boot -- sometime around 6.14 or 6.15 cycle.

Best regards,
Alexey