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SubjectRe: [V2,2/2] drivers: i2c: qup: Fix error handling
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On 5/6/2016 5:31 AM, Sricharan R wrote:
> Among the bus errors reported from the QUP_MASTER_STATUS register
> only NACK is considered and transfer gets suspended, while
> other errors are ignored. Correct this and suspend the transfer
> for other errors as well. This avoids unnessecary 'timeouts' which
> happens when waiting for events that would never happen when there
> is already an error condition on the bus.
>
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> Reviewed-by: Andy Gross <andy.gross@linaro.org>
Hi Sricharan,
Looks good to me. Tested on QDF2432 platform.

Reviewed-by: Naveen Kaje <nkaje@codeaurora.org>
Tested-by: Naveen Kaje <nkaje@codeaurora.org>

> ---
> drivers/i2c/busses/i2c-qup.c | 42 +++++++++++++++++++++++++++++-------------
> 1 file changed, 29 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
> index 8620e99..af52a47 100644
> --- a/drivers/i2c/busses/i2c-qup.c
> +++ b/drivers/i2c/busses/i2c-qup.c
> @@ -310,6 +310,7 @@ static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
> u32 opflags;
> u32 status;
> u32 shift = __ffs(op);
> + int ret = 0;
>
> len *= qup->one_byte_t;
> /* timeout after a wait of twice the max time */
> @@ -321,18 +322,31 @@ static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
>
> if (((opflags & op) >> shift) == val) {
> if ((op == QUP_OUT_NOT_EMPTY) && qup->is_last) {
> - if (!(status & I2C_STATUS_BUS_ACTIVE))
> - return 0;
> + if (!(status & I2C_STATUS_BUS_ACTIVE)) {
> + ret = 0;
> + goto done;
> + }
> } else {
> - return 0;
> + ret = 0;
> + goto done;
> }
> }
>
> - if (time_after(jiffies, timeout))
> - return -ETIMEDOUT;
> -
> + if (time_after(jiffies, timeout)) {
> + ret = -ETIMEDOUT;
> + goto done;
> + }
> usleep_range(len, len * 2);
> }
> +
> +done:
> + if (qup->bus_err || qup->qup_err) {
> + if (qup->bus_err & QUP_I2C_NACK_FLAG)
> + dev_err(qup->dev, "NACK from %x\n", qup->msg->addr);
> + ret = -EIO;
> + }
> +
> + return ret;
> }
>
> static void qup_i2c_set_write_mode_v2(struct qup_i2c_dev *qup,
> @@ -796,7 +810,6 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
> if (qup->bus_err & QUP_I2C_NACK_FLAG) {
> msg--;
> dev_err(qup->dev, "NACK from %x\n", msg->addr);
> - ret = -EIO;
>
> if (qup_i2c_change_state(qup, QUP_RUN_STATE)) {
> dev_err(qup->dev, "change to run state timed out");
> @@ -818,6 +831,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
>
> qup_i2c_rel_dma(qup);
> }
> + ret = -EIO;
> }
>
> dma_unmap_sg(qup->dev, qup->btx.sg, tx_nents, DMA_TO_DEVICE);
> @@ -841,9 +855,6 @@ static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
> if (ret)
> goto out;
>
> - qup->bus_err = 0;
> - qup->qup_err = 0;
> -
> writel(0, qup->base + QUP_MX_INPUT_CNT);
> writel(0, qup->base + QUP_MX_OUTPUT_CNT);
>
> @@ -882,10 +893,9 @@ static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
> }
>
> if (qup->bus_err || qup->qup_err) {
> - if (qup->bus_err & QUP_I2C_NACK_FLAG) {
> + if (qup->bus_err & QUP_I2C_NACK_FLAG)
> dev_err(qup->dev, "NACK from %x\n", msg->addr);
> - ret = -EIO;
> - }
> + ret = -EIO;
> }
>
> return ret;
> @@ -1178,6 +1188,9 @@ static int qup_i2c_xfer(struct i2c_adapter *adap,
> if (ret < 0)
> goto out;
>
> + qup->bus_err = 0;
> + qup->qup_err = 0;
> +
> writel(1, qup->base + QUP_SW_RESET);
> ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
> if (ret)
> @@ -1227,6 +1240,9 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
> struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
> int ret, len, idx = 0, use_dma = 0;
>
> + qup->bus_err = 0;
> + qup->qup_err = 0;
> +
> ret = pm_runtime_get_sync(qup->dev);
> if (ret < 0)
> goto out;

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