Re: [PATCH 2/3] i2c: qcom-geni: Propagate GENI_ABORT_DONE to geni_i2c_abort_xfer()

Andrew Halaney
2022-07-19T20:51:28Z

On Sat, Jul 16, 2022 at 08:50:26PM -0700, Bjorn Andersson wrote:
> Waiting for M_CMD_ABORT_EN in geni_i2c_abort_xfer() races with the
> interrupt handler which will read and clear the abort bit, the result is
> that every abort attempt takes 1 second and is followed by a message
> about the abort having times out.
>
> Introduce a new state variable to carry the abort_done state from the
> interrupt handler back to geni_i2c_abort_xfer().
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> drivers/i2c/busses/i2c-qcom-geni.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
> index 3bec7c782824..e212e7ae7ad2 100644
> --- a/drivers/i2c/busses/i2c-qcom-geni.c
> +++ b/drivers/i2c/busses/i2c-qcom-geni.c
> @@ -97,6 +97,7 @@ struct geni_i2c_dev {
> struct dma_chan *tx_c;
> struct dma_chan *rx_c;
> bool gpi_mode;
> + bool abort_done;
> };
>
> struct geni_i2c_err_log {
> @@ -203,9 +204,14 @@ static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
> dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
> gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
>
> - if (err != NACK && err != GENI_ABORT_DONE) {
> + switch (err) {
> + case GENI_ABORT_DONE:
> + gi2c->abort_done = true;
> + break;
> + default:
> dev_err(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
> geni_i2c_err_misc(gi2c);
> + break;
> }
> }
>

If I'm reading this right this changes the behavior on a NACK error now,
right? Was that intentional?

Otherwise looks good to me.

> @@ -311,21 +317,21 @@ static irqreturn_t geni_i2c_irq(int irq, void *dev)
>
> static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
> {
> - u32 val;
> unsigned long time_left = ABORT_TIMEOUT;
> unsigned long flags;
>
> spin_lock_irqsave(&gi2c->lock, flags);
> geni_i2c_err(gi2c, GENI_TIMEOUT);
> gi2c->cur = NULL;
> + gi2c->abort_done = false;
> geni_se_abort_m_cmd(&gi2c->se);
> spin_unlock_irqrestore(&gi2c->lock, flags);
> +
> do {
> time_left = wait_for_completion_timeout(&gi2c->done, time_left);
> - val = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
> - } while (!(val & M_CMD_ABORT_EN) && time_left);
> + } while (!gi2c->abort_done && time_left);
>
> - if (!(val & M_CMD_ABORT_EN))
> + if (!time_left)
> dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
> }
>
> --
> 2.35.1
>