On Tue 13 Oct 16:25 CDT 2020, Douglas Anderson wrote:
> This reverts commit 02b9aec59243c6240fc42884acc958602146ddf6.
>
> As talked about in the patch ("soc: qcom: geni: More properly switch
> to DMA mode"), swapping the order of geni_se_setup_m_cmd() and
> geni_se_xx_dma_prep() can sometimes cause corrupted transfers. Thus
> we traded one problem for another. Now that we've debugged the
> problem further and fixed the geni helper functions to more disable
> FIFO interrupts when we move to DMA mode we can revert it and end up
> with (hopefully) zero problems!
>
> To be explicit, the patch ("soc: qcom: geni: More properly switch
> to DMA mode") is a prerequisite for this one.
>
> Fixes: 02b9aec59243 ("i2c: i2c-qcom-geni: Fix DMA transfer race")
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> Reviewed-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
> Tested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Wolfram, would you like to pick this patch or would you prefer that it
goes together with the other two through the soc tree?
Per Doug's description it has a functional dependency on patch 1, but as
long as all three patches makes it into v5.11 I'm okay with either way.
Regards,
Bjorn
> ---
>
> (no changes since v1)
>
> drivers/i2c/busses/i2c-qcom-geni.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index dead5db3315a..32b2a9921b14 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -367,6 +367,7 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> geni_se_select_mode(se, GENI_SE_FIFO);
>
> writel_relaxed(len, se->base + SE_I2C_RX_TRANS_LEN);
> + geni_se_setup_m_cmd(se, I2C_READ, m_param);
>
> if (dma_buf && geni_se_rx_dma_prep(se, dma_buf, len, &rx_dma)) {
> geni_se_select_mode(se, GENI_SE_FIFO);
> @@ -374,8 +375,6 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> dma_buf = NULL;
> }
>
> - geni_se_setup_m_cmd(se, I2C_READ, m_param);
> -
> time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
> if (!time_left)
> geni_i2c_abort_xfer(gi2c);
> @@ -409,6 +408,7 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> geni_se_select_mode(se, GENI_SE_FIFO);
>
> writel_relaxed(len, se->base + SE_I2C_TX_TRANS_LEN);
> + geni_se_setup_m_cmd(se, I2C_WRITE, m_param);
>
> if (dma_buf && geni_se_tx_dma_prep(se, dma_buf, len, &tx_dma)) {
> geni_se_select_mode(se, GENI_SE_FIFO);
> @@ -416,8 +416,6 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
> dma_buf = NULL;
> }
>
> - geni_se_setup_m_cmd(se, I2C_WRITE, m_param);
> -
> if (!dma_buf) /* Get FIFO IRQ */
> writel_relaxed(1, se->base + SE_GENI_TX_WATERMARK_REG);
>
> --
> 2.28.0.1011.ga647a8990f-goog
>
