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Date:   Sun, 07 Aug 2022 15:31:17 +0000
To:     Robin Reckmann <robin.reckmann@googlemail.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        =?utf-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>
From:   Caleb Connolly <caleb@connolly.tech>
Cc:     Robin Reckmann <robin.reckmann@gmail.com>,
        linux-arm-msm@vger.kernel.org, linux-i2c@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org
Reply-To: Caleb Connolly <caleb@connolly.tech>
Subject: Re: [PATCH] i2c: qcom-geni: Fix GPI DMA buffer sync-back
Message-ID: <653e93e7-6bdc-3498-7719-f3a7860dd245@connolly.tech>
In-Reply-To: <20220807140455.409417-1-robin.reckmann@gmail.com>
References: <20220807140455.409417-1-robin.reckmann@gmail.com>
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On 07/08/2022 15:04, Robin Reckmann wrote:
> Fix i2c transfers using GPI DMA mode for all message types that do not se=
t
> the I2C_M_DMA_SAFE flag (e.g. SMBus "read byte").
>
> In this case a bounce buffer is returned by i2c_get_dma_safe_msg_buf(),
> and it has to synced back to the message after the transfer is done.
>
> Add missing assignment of dma buffer in geni_i2c_gpi().
>
> Set xferred in i2c_put_dma_safe_msg_buf() to true in case of no error to
> ensure the sync-back of this dma buffer to the message.
Thanks for sending this, it fixes GPI DMA on the PocoPhone F1 and Pixel 3!
>
> Signed-off-by: Robin Reckmann <robin.reckmann@gmail.com>Reviewed-by: Cale=
b Connolly <caleb@connolly.tech>
> ---
>   drivers/i2c/busses/i2c-qcom-geni.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-=
qcom-geni.c
> index 6ac402ea58fb..d3541e94794e 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -484,12 +484,12 @@ static void geni_i2c_gpi_unmap(struct geni_i2c_dev =
*gi2c, struct i2c_msg *msg,
>   {
>   =09if (tx_buf) {
>   =09=09dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_=
DEVICE);
> -=09=09i2c_put_dma_safe_msg_buf(tx_buf, msg, false);
> +=09=09i2c_put_dma_safe_msg_buf(tx_buf, msg, !gi2c->err);
>   =09}
>
>   =09if (rx_buf) {
>   =09=09dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FRO=
M_DEVICE);
> -=09=09i2c_put_dma_safe_msg_buf(rx_buf, msg, false);
> +=09=09i2c_put_dma_safe_msg_buf(rx_buf, msg, !gi2c->err);
>   =09}
>   }
>
> @@ -553,6 +553,7 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, st=
ruct i2c_msg *msg,
>   =09desc->callback_param =3D gi2c;
>
>   =09dmaengine_submit(desc);
> +=09*buf =3D dma_buf;
>   =09*dma_addr_p =3D addr;
>
>   =09return 0;
> --
> 2.25.1
>

--
Kind Regards,
Caleb