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Subject[PATCH v2] i2c: cadence: try reset when master receive arbitration lost
Date
When the adapter receive arbitration lost error interrupts,
cdns_i2c_master_xfer return to the caller directly instead of resetting
the adapter which resulted in the adapter being out of control.

So when driver detect err_status such as arbitration lost,
then try to repair and fix it.

Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Shikai Wang <sxauwsk@163.com>
---
drivers/i2c/busses/i2c-cadence.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index b13605718291..595b0d56ff1a 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -548,10 +548,6 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK,
CDNS_I2C_IDR_OFFSET);

- /* If it is bus arbitration error, try again */
- if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
- return -EAGAIN;
-
return 0;
}

@@ -624,6 +620,12 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
if (id->err_status) {
cdns_i2c_master_reset(adap);

+ /* If it is bus arbitration error, try again */
+ if (id->err_status & CDNS_I2C_IXR_ARB_LOST) {
+ ret = -EAGAIN;
+ goto out;
+ }
+
if (id->err_status & CDNS_I2C_IXR_NACK) {
ret = -ENXIO;
goto out;
--
2.19.2

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