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i2c: imx: Check for I2SR_IAL after every byte 

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>
zero-sugar-mainline-defconfig
Christian Eggers 2020-10-09 13:03:19 +02:00 committed by Wolfram Sang
parent 384a9565f7
commit 1de67a3dee
1 changed files with 10 additions and 0 deletions
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10
drivers/i2c/busses/i2c-imx.c
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@ -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;