On Wed, Oct 07, 2020 at 10:45:23AM +0200, Christian Eggers wrote:
> Arbitration Lost (IAL) can happen after every single byte transfer. If
> arbitration is lost, the I2C hardware will autonomously switch from
> master mode to slave. If a transfer is not aborted in this state,
> consecutive transfers will not be executed by the hardware and will
> timeout.
>
> Signed-off-by: Christian Eggers <ceggers@xxxxxxx>
> Tested (not extensively) on Vybrid VF500 (Toradex VF50):
> Tested-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Thank you!
> ---
> drivers/i2c/busses/i2c-imx.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index cbdcab73a055..63575af41c09 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -490,6 +490,16 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic)
> dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
> return -ETIMEDOUT;
> }
> +
> + /* check for arbitration lost */
> + if (i2c_imx->i2csr & I2SR_IAL) {
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__);
> + i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
> +
> + i2c_imx->i2csr = 0;
> + return -EAGAIN;
> + }
> +
> dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
> i2c_imx->i2csr = 0;
> return 0;
> --
> Christian Eggers
> Embedded software developer
>
> Arnold & Richter Cine Technik GmbH & Co. Betriebs KG
> Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRA 57918
> Persoenlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH
> Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRB 54477
> Geschaeftsfuehrer: Dr. Michael Neuhaeuser; Stephan Schenk; Walter Trauninger; Markus Zeiler
>
>
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
