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 <[email protected]> > Tested (not extensively) on Vybrid VF500 (Toradex VF50): > Tested-by: Krzysztof Kozlowski <[email protected]> > Cc: [email protected]
Acked-by: Oleksij Rempel <[email protected]> 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 |
