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i2c: imx: Check for I2SR_IAL after every byte 

commit 1de67a3dee upstream.

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>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christian Eggers 2020-10-09 13:03:19 +02:00 committed by Greg Kroah-Hartman
parent 83366a7b2d
commit 83d5121c3b
1 changed files with 10 additions and 0 deletions
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10
drivers/i2c/busses/i2c-imx.c
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@ -470,6 +470,16 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
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;