Re: [PATCH v2] i2c: cadence: try reset when master receive arbitration lost
On Sat, Mar 09, 2019 at 10:44:52AM +0100, Wolfram Sang wrote: > On Sat, Feb 23, 2019 at 10:48:43AM +0100, Wolfram Sang wrote: > > On Tue, Feb 19, 2019 at 09:24:47AM +0800, Shikai Wang wrote: > > > 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. > > > > Just checking because resetting looks like a big hammer to me: there is > > no way to gracefully recover form 'arbitration lost' interrupt? > > I am still wondering about this but since it is acked by the maintainer: > > Applied to for-current, thanks! Oops, I was mixing this up with [PATCHv4] i2c: cadence: Fix the driver in interrupt flurry case This one doesn't have an ack from Michal. Dropping it again. signature.asc Description: PGP signature
Re: [PATCH v2] i2c: cadence: try reset when master receive arbitration lost
On Sat, Feb 23, 2019 at 10:48:43AM +0100, Wolfram Sang wrote: > On Tue, Feb 19, 2019 at 09:24:47AM +0800, Shikai Wang wrote: > > 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. > > Just checking because resetting looks like a big hammer to me: there is > no way to gracefully recover form 'arbitration lost' interrupt? I am still wondering about this but since it is acked by the maintainer: Applied to for-current, thanks! signature.asc Description: PGP signature
Re: [PATCH v2] i2c: cadence: try reset when master receive arbitration lost
On Tue, Feb 19, 2019 at 09:24:47AM +0800, Shikai Wang wrote: > 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. Just checking because resetting looks like a big hammer to me: there is no way to gracefully recover form 'arbitration lost' interrupt? signature.asc Description: PGP signature
[PATCH v2] i2c: cadence: try reset when master receive arbitration lost
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
Signed-off-by: Shikai Wang
---
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
