4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Grygorii Tertychnyi <grembeter@xxxxxxxxx>
[ Upstream commit 5a72477273066b5b357801ab2d315ef14949d402 ]
Setting IACK bit when core is disabled does not clear the "Interrupt Flag"
bit in the status register, and the interrupt remains pending.
Sometimes it causes failure for the very first message transfer, that is
usually a device probe.
Hence, set IACK bit after core is enabled to clear pending interrupt.
Fixes: 18f98b1e3147 ("[PATCH] i2c: New bus driver for the OpenCores I2C controller")
Signed-off-by: Grygorii Tertychnyi <grygorii.tertychnyi@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Peter Korsgaard <peter@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-ocores.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index aa852028d8c15..7646d6c99179b 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -290,8 +290,8 @@ static int ocores_init(struct device *dev, struct ocores_i2c *i2c)
oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8);
/* Init the device */
- oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN | OCI2C_CTRL_EN);
+ oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
return 0;
}
--
2.43.0
