On Mon, 29 Jan 2024 at 08:10, Viken Dadhaniya <quic_vdadhani@xxxxxxxxxxx> wrote:
>
> For i2c read operation, we are getting gsi mode timeout due
> to malformed TRE(Transfer Ring Element). Currently we are
> configuring incorrect TRE sequence in gpi driver
> (drivers/dma/qcom/gpi.c) as below
>
> - Sets up CONFIG
> - Sets up DMA tre
> - Sets up GO tre
>
> As per HPG(Hardware programming guide), We should configure TREs in below
> sequence for any i2c transfer
>
> - Sets up CONFIG tre
> - Sets up GO tre
> - Sets up DMA tre
It is not clear how this is relevant and/or affected by swapping
I2C_WRITE and I2C_READ gpi calls.
>
> For only write operation or write followed by read operation,
> existing software sequence is correct.
>
> for only read operation, TRE sequence need to be corrected.
> Hence, we have changed the sequence to submit GO tre before DMA tre.
>
> Tested covering i2c read/write transfer on QCM6490 RB3 board.
Please read Documentation/process/submitting-patches.rst, understand
it and write a proper commit message.
>
> Signed-off-by: Viken Dadhaniya <quic_vdadhani@xxxxxxxxxxx>
> Fixes: commit d8703554f4de ("i2c: qcom-geni: Add support for GPI DMA")
As it was pointed out, this line shows ignorance of the mentioned file
and of the existing community practices.
> ---
> v1 -> v2:
> - Remove redundant check.
> - update commit log.
> - add fix tag.
> ---
> ---
> drivers/i2c/busses/i2c-qcom-geni.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index 0d2e7171e3a6..da94df466e83 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -613,20 +613,20 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
>
> peripheral.addr = msgs[i].addr;
>
> + ret = geni_i2c_gpi(gi2c, &msgs[i], &config,
> + &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
> + if (ret)
> + goto err;
> +
> if (msgs[i].flags & I2C_M_RD) {
> ret = geni_i2c_gpi(gi2c, &msgs[i], &config,
> &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
> if (ret)
> goto err;
> - }
> -
> - ret = geni_i2c_gpi(gi2c, &msgs[i], &config,
> - &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
> - if (ret)
> - goto err;
>
> - if (msgs[i].flags & I2C_M_RD)
> dma_async_issue_pending(gi2c->rx_c);
> + }
> +
> dma_async_issue_pending(gi2c->tx_c);
>
> timeout = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>
>
--
With best wishes
Dmitry
