On Wed, Jul 20, 2022 at 12:33:13PM +0200, Daniel Brát wrote:
> Fixes an issue where the driver in case of NACK error would not properly
> terminate the tranfer, resulting in BSC not sending the STOP condition
> until just before the next xfer.
>
> Signed-off-by: Daniel Brát <danek.brat@xxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-bcm283x.c | 23 +++++++++++++++--------
> 1 file changed, 15 insertions(+), 8 deletions(-)
Applied, thanks
Sascha
>
> diff --git a/drivers/i2c/busses/i2c-bcm283x.c b/drivers/i2c/busses/i2c-bcm283x.c
> index 097f73d983..fdba3b91bd 100644
> --- a/drivers/i2c/busses/i2c-bcm283x.c
> +++ b/drivers/i2c/busses/i2c-bcm283x.c
> @@ -147,7 +147,7 @@ static int bcm283x_i2c_msg_xfer(struct bcm283x_i2c *bcm_i2c,
>
> if (ret) {
> dev_err(dev, "timeout: 10bit read initilization\n");
> - return ret;
> + goto out;
> }
> if (reg_s & BSC_S_ERR)
> goto nack;
> @@ -178,7 +178,7 @@ static int bcm283x_i2c_msg_xfer(struct bcm283x_i2c *bcm_i2c,
>
> if (ret) {
> dev_err(dev, "timeout: waiting for data in FIFO\n");
> - return ret;
> + goto out;
> }
> if (reg_s & BSC_S_ERR)
> goto nack;
> @@ -197,7 +197,7 @@ static int bcm283x_i2c_msg_xfer(struct bcm283x_i2c *bcm_i2c,
>
> if (ret) {
> dev_err(dev, "timeout: waiting for space in FIFO\n");
> - return ret;
> + goto out;
> }
> if (reg_s & BSC_S_ERR)
> goto nack;
> @@ -216,16 +216,23 @@ static int bcm283x_i2c_msg_xfer(struct bcm283x_i2c *bcm_i2c,
>
> if (ret) {
> dev_err(dev, "timeout: waiting for transfer to end\n");
> - return ret;
> + goto out;
> }
> if (reg_s & BSC_S_ERR)
> goto nack;
> - writel(BSC_S_DONE | BSC_S_ERR | BSC_S_CLKT, &bcm_i2c->regs->s);
> - writel(BSC_C_CLEAR1 | BSC_C_I2CEN, &bcm_i2c->regs->c);
> - return 0;
> + goto out;
> nack:
> dev_dbg(dev, "device with addr %x didn't ACK\n", msg->addr);
> - return -EREMOTEIO;
> + writel(BSC_S_ERR, &bcm_i2c->regs->s);
> + timeout = calc_byte_timeout_us(bcm_i2c->bitrate);
> + // Wait for end of transfer so BSC has time to send STOP condition
> + readl_poll_timeout(&bcm_i2c->regs->s, reg_s, ~reg_s & BSC_S_TA, timeout);
> + ret = -EREMOTEIO;
> +out:
> + // Return to default state for next xfer
> + writel(BSC_S_DONE | BSC_S_ERR | BSC_S_CLKT, &bcm_i2c->regs->s);
> + writel(BSC_C_CLEAR1 | BSC_C_I2CEN, &bcm_i2c->regs->c);
> + return ret;
> }
>
> static int bcm283x_i2c_xfer(struct i2c_adapter *adapter,
> --
> 2.37.0
>
>
>
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