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@arri.de Tested (not extensively) on Vybrid VF500 (Toradex VF50): Tested-by: Krzysztof Kozlowski krzk@kernel.org Cc: stable@vger.kernel.org
Acked-by: Oleksij Rempel o.rempel@pengutronix.de
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
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