It has been observed through repeated testing (250 boots) that in the
10% of the cases the RDACM21 initialization sequence errors out due a
timeout waiting for the OV490 firmware to complete its boot phase.

Albeit being the current timeout relatively large (300-600 milliseconds),
doubling it reduces the sporadic error rate down to 1 over an 80 boot
sequences test run.

The firmware boot delay is unfortunately not characterized in the camera
module manual.

Fixes: a59f853b3b4b ("media: i2c: Add driver for RDACM21 camera module")
Signed-off-by: Jacopo Mondi <jacopo+rene...@jmondi.org>
---
 drivers/media/i2c/rdacm21.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
index 50a9b0d8255d..07cf077d8efd 100644
--- a/drivers/media/i2c/rdacm21.c
+++ b/drivers/media/i2c/rdacm21.c
@@ -53,7 +53,7 @@
 #define OV490_PID                      0x8080300a
 #define OV490_VER                      0x8080300b
 #define OV490_PID_TIMEOUT              20
-#define OV490_OUTPUT_EN_TIMEOUT                300
+#define OV490_OUTPUT_EN_TIMEOUT                600
 
 #define OV490_GPIO0                    BIT(0)
 #define OV490_SPWDN0                   BIT(0)
-- 
2.30.0

Reply via email to