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authorChristian Eggers <ceggers@arri.de>2020-10-09 14:03:19 +0300
committerWolfram Sang <wsa@kernel.org>2020-12-02 23:28:20 +0300
commit1de67a3dee7a279ebe4d892b359fe3696938ec15 (patch)
tree77db1ed346aa4ed5548b2235951f92f09024a6a0 /drivers/i2c
parent384a9565f70a876c2e78e58c5ca0bbf0547e4f6d (diff)
downloadlinux-1de67a3dee7a279ebe4d892b359fe3696938ec15.tar.xz
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>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-imx.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 39e98d216016..a2abae124342 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;