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Revert "i2c: i2c-qcom-geni: Fix DMA transfer race" 

This reverts commit 02b9aec592.

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: 02b9aec592 ("i2c: i2c-qcom-geni: Fix DMA transfer race")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20201013142448.v2.2.I7b22281453b8a18ab16ef2bfd4c641fb1cc6a92c@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
zero-sugar-mainline-defconfig
Douglas Anderson 2020-10-13 14:25:29 -07:00 committed by Bjorn Andersson
parent 4b6ea87be4
commit 9cb4c67d77
1 changed files with 2 additions and 4 deletions
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6
drivers/i2c/busses/i2c-qcom-geni.c
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@ -366,6 +366,7 @@ 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);
@ -373,8 +374,6 @@ 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);
@ -408,6 +407,7 @@ 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);
@ -415,8 +415,6 @@ 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);