Re: [PATCH v2 3/5] arm64: dts: qcom: sc7280: Add dma-coherent property into venus node
Vishnu Reddy <[email protected]>
| Newsgroups | org.kernel.vger.linux-media,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.stable |
|---|---|
| Message-ID | <[email protected]> |
On 8/19/2026 12:46 PM, Krzysztof Kozlowski wrote:
> On Tue, Aug 18, 2026 at 09:24:16PM +0530, Vishnu Reddy wrote:
>> The venus video hardware on SC7280 is IO-coherent hardware: even though
>> the driver does dma_sync*() calls for the input and output buffers, the
>> venus node still needs to declare dma-coherent so that the DMA mapping
>> layer relies on this hardware level snooping to keep the CPU cache and
>> the DMA buffers in sync. This avoids the unnecessary cache clean or
>> invalidate operations performed by the dma_sync*() calls, which are not
>> required once hardware level snooping is enabled via dma-coherent.
>>
>> Add the dma-coherent property to the venus node to describe this
>> hardware capability.
>>
>> Fixes: 37613aee2179 ("arm64: dts: qcom: sc7280: Add venus DT node")
>> Cc: [email protected]
> Nope, nothing to be fixed here. I already said it last time.
I'll remove it.
> Best regards,
> Krzysztof
>
>