| Message ID | 20201008155154.2.I7b22281453b8a18ab16ef2bfd4c641fb1cc6a92c@changeid |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: i2c-qcom-geni: More properly fix the DMA race | expand |
Quoting Douglas Anderson (2020-10-08 15:52:34) > 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@chromium.org> > --- Reviewed-by: Stephen Boyd <swboyd@chromium.org>
On 10/9/2020 4:22 AM, 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@chromium.org> Reviewed-by: Akash Asthana <akashast@codeaurora.org>
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);
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@chromium.org> --- drivers/i2c/busses/i2c-qcom-geni.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)