| Message ID | 20240105125258.2470397-1-sai.pavan.boddu@amd.com |
|---|---|
| State | New |
| Headers | show |
| Series | i2c: cadence: Avoid fifo clear after start | expand |
On 1/5/24 13:52, Sai Pavan Boddu wrote: > Driver unintentionally programs ctrl reg to clear fifo which is > happening after start of transaction, this was not the case previously > as it was read-modified-write. This issue breaks i2c reads on QEMU as > i2c-read is done before guest starts programming ctrl register. > > Fixes: ff0cf7bca6309 ("i2c: cadence: Remove unnecessary register reads") > Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com> > --- > drivers/i2c/busses/i2c-cadence.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c > index de3f58b60dce..6f7d753a8197 100644 > --- a/drivers/i2c/busses/i2c-cadence.c > +++ b/drivers/i2c/busses/i2c-cadence.c > @@ -633,6 +633,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id) > > if (hold_clear) { > ctrl_reg &= ~CDNS_I2C_CR_HOLD; > + ctrl_reg &= ~CDNS_I2C_CR_CLR_FIFO; > /* > * In case of Xilinx Zynq SOC, clear the HOLD bit before transfer size > * register reaches '0'. This is an IP bug which causes transfer size Acked-by: Michal Simek <michal.simek@amd.com> Thanks, Michal
diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c index de3f58b60dce..6f7d753a8197 100644 --- a/drivers/i2c/busses/i2c-cadence.c +++ b/drivers/i2c/busses/i2c-cadence.c @@ -633,6 +633,7 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id) if (hold_clear) { ctrl_reg &= ~CDNS_I2C_CR_HOLD; + ctrl_reg &= ~CDNS_I2C_CR_CLR_FIFO; /* * In case of Xilinx Zynq SOC, clear the HOLD bit before transfer size * register reaches '0'. This is an IP bug which causes transfer size
Driver unintentionally programs ctrl reg to clear fifo which is happening after start of transaction, this was not the case previously as it was read-modified-write. This issue breaks i2c reads on QEMU as i2c-read is done before guest starts programming ctrl register. Fixes: ff0cf7bca6309 ("i2c: cadence: Remove unnecessary register reads") Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com> --- drivers/i2c/busses/i2c-cadence.c | 1 + 1 file changed, 1 insertion(+)