| Message ID | 20201006160814.22047-3-ceggers@arri.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: imx: Fix handling of arbitration loss | expand |
On Tue, 6 Oct 2020 at 18:11, Christian Eggers <ceggers@arri.de> 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> > Cc: stable@vger.kernel.org Where is the tested-by tag from me? Best regards, Krzysztof
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;
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> Cc: stable@vger.kernel.org --- drivers/i2c/busses/i2c-imx.c | 10 ++++++++++ 1 file changed, 10 insertions(+)