Re: [PATCH 4/9] PCI: epf-mhi: Simulate async read/write using iATU

From: Krzysztof Wilczyński
Date: Wed Dec 13 2023 - 13:49:39 EST


Hello,

> Even though iATU only supports synchronous read/write, the MHI stack may
> call async read/write callbacks without knowing the limitations of the
> controller driver. So in order to maintain compatibility, let's simulate
> async read/write operation with iATU by invoking the completion callback
> after memcpy.
>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> ---
> drivers/pci/endpoint/functions/pci-epf-mhi.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> index 34e7191f9508..7214f4da733b 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> @@ -234,6 +234,9 @@ static int pci_epf_mhi_iatu_read(struct mhi_ep_cntrl *mhi_cntrl,
>
> mutex_unlock(&epf_mhi->lock);
>
> + if (buf_info->cb)
> + buf_info->cb(buf_info);
> +
> return 0;
> }
>
> @@ -262,6 +265,9 @@ static int pci_epf_mhi_iatu_write(struct mhi_ep_cntrl *mhi_cntrl,
>
> mutex_unlock(&epf_mhi->lock);
>
> + if (buf_info->cb)
> + buf_info->cb(buf_info);
> +
> return 0;
> }

Looks good!

Reviewed-by: Krzysztof Wilczyński <kw@xxxxxxxxx>

Krzysztof