Re: [PATCH net v2] net: stmmac: dwmac-qcom-ethqos: Configure host DMA width

From: Simon Horman
Date: Fri Jun 07 2024 - 07:31:43 EST


On Wed, Jun 05, 2024 at 11:57:18AM -0700, Sagar Cheluvegowda wrote:
> Commit 070246e4674b ("net: stmmac: Fix for mismatched host/device DMA
> address width") added support in the stmmac driver for platform drivers
> to indicate the host DMA width, but left it up to authors of the
> specific platforms to indicate if their width differed from the addr64
> register read from the MAC itself.
>
> Qualcomm's EMAC4 integration supports only up to 36 bit width (as
> opposed to the addr64 register indicating 40 bit width). Let's indicate
> that in the platform driver to avoid a scenario where the driver will
> allocate descriptors of size that is supported by the CPU which in our
> case is 36 bit, but as the addr64 register is still capable of 40 bits
> the device will use two descriptors as one address.
>
> Fixes: 8c4d92e82d50 ("net: stmmac: dwmac-qcom-ethqos: add support for emac4 on sa8775p platforms")
> Signed-off-by: Sagar Cheluvegowda <quic_scheluve@xxxxxxxxxxx>
> ---
> Changes in v2:
> Fix commit message to include a commit body
> Replace the proper fixes tag
> Remove the change-Id
> - Link to v1: https://lore.kernel.org/r/20240529-configure_ethernet_host_dma_width-v1-1-3f2707851adf@xxxxxxxxxxx

Thanks,

this change looks good to me - the usage of dma_addr_width is in line with
my understanding of how it is intended to be used.

And, AFAICS, the changes in v2 address the review of v1.

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>

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