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@xxxxxxx>
---
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@xxxxxxx>
Thanks,
Michal
