leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

i2c: imx: Check for I2SR_IAL after every byte

Browse Source 
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>
This commit is contained in:
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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/i2c/busses/i2c-imx.c
View File

@ -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__); dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
return -ETIMEDOUT; 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__); dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
i2c_imx->i2csr = 0; i2c_imx->i2csr = 0;
return 0; return 0;