| Message ID | 20210319164148.199192-12-jacopo+renesas@jmondi.org (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Kieran Bingham |
| Headers | show |
| Series | media: gmsl: Reliability improvement | expand |
Hi Jacopo, s/dealy/delay/ in $SUBJECT On 19/03/2021 16:41, Jacopo Mondi wrote: > Add a delay after the OV490 chip is put in reset state. The reset > signal shall be held for at least 250 useconds. > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > --- > drivers/media/i2c/rdacm21.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c > index babd14b21252..875bec9f7904 100644 > --- a/drivers/media/i2c/rdacm21.c > +++ b/drivers/media/i2c/rdacm21.c > @@ -448,7 +448,10 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) > if (ret) > return ret; > > - /* Enable GPIO1 and hold OV490 in reset during max9271 configuration. */ > + /* > + * Enable GPIO1 and hold OV490 in reset during max9271 configuration. > + * The reset signal has to be asserted for at least 250 useconds. > + */ > ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT); > if (ret) > return ret; > @@ -456,6 +459,7 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) > ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT); > if (ret) > return ret; > + usleep_range(250, 500); Aha, for a second there I thought the comment meant it had to be asserted for 250 uS before clearing it again. But it's 250 uS before using the OV490. Perhaps possible to update the comment a little, but nothing that matters. Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > ret = max9271_configure_gmsl_link(&dev->serializer); > if (ret) >
Hi Jacopo, Thank you for the patch. On Fri, Mar 19, 2021 at 04:49:44PM +0000, Kieran Bingham wrote: > Hi Jacopo, > > s/dealy/delay/ in $SUBJECT > > On 19/03/2021 16:41, Jacopo Mondi wrote: > > Add a delay after the OV490 chip is put in reset state. The reset > > signal shall be held for at least 250 useconds. > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > --- > > drivers/media/i2c/rdacm21.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c > > index babd14b21252..875bec9f7904 100644 > > --- a/drivers/media/i2c/rdacm21.c > > +++ b/drivers/media/i2c/rdacm21.c > > @@ -448,7 +448,10 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) > > if (ret) > > return ret; > > > > - /* Enable GPIO1 and hold OV490 in reset during max9271 configuration. */ > > + /* > > + * Enable GPIO1 and hold OV490 in reset during max9271 configuration. > > + * The reset signal has to be asserted for at least 250 useconds. > > + */ > > ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT); > > if (ret) > > return ret; > > @@ -456,6 +459,7 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) > > ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT); > > if (ret) > > return ret; > > + usleep_range(250, 500); > > Aha, for a second there I thought the comment meant it had to be > asserted for 250 uS before clearing it again. But it's 250 uS before > using the OV490. > > Perhaps possible to update the comment a little, but nothing that matters. The commit message and comment should match the code, especially given that I'm not sure here which of the two is actually incorrect. I suspect the sleep is actually in the wrong location. > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > > > > ret = max9271_configure_gmsl_link(&dev->serializer); > > if (ret) > >
Hi Laurent, Kieran, On Sat, Mar 20, 2021 at 05:52:18PM +0200, Laurent Pinchart wrote: > Hi Jacopo, > > Thank you for the patch. > > On Fri, Mar 19, 2021 at 04:49:44PM +0000, Kieran Bingham wrote: > > Hi Jacopo, > > > > s/dealy/delay/ in $SUBJECT > > > > On 19/03/2021 16:41, Jacopo Mondi wrote: > > > Add a delay after the OV490 chip is put in reset state. The reset > > > signal shall be held for at least 250 useconds. > > > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > > --- > > > drivers/media/i2c/rdacm21.c | 6 +++++- > > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c > > > index babd14b21252..875bec9f7904 100644 > > > --- a/drivers/media/i2c/rdacm21.c > > > +++ b/drivers/media/i2c/rdacm21.c > > > @@ -448,7 +448,10 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) > > > if (ret) > > > return ret; > > > > > > - /* Enable GPIO1 and hold OV490 in reset during max9271 configuration. */ > > > + /* > > > + * Enable GPIO1 and hold OV490 in reset during max9271 configuration. > > > + * The reset signal has to be asserted for at least 250 useconds. > > > + */ > > > ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT); > > > if (ret) > > > return ret; > > > @@ -456,6 +459,7 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) > > > ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT); > > > if (ret) > > > return ret; > > > + usleep_range(250, 500); > > > > Aha, for a second there I thought the comment meant it had to be > > asserted for 250 uS before clearing it again. But it's 250 uS before > > using the OV490. No, it's 250usecond before releasing it. After the OV490 is released from reset there's a 3-5 milliseconds sleep below. > > > > Perhaps possible to update the comment a little, but nothing that matters. > > The commit message and comment should match the code, especially given They do if I'm not mistaken. > that I'm not sure here which of the two is actually incorrect. I suspect > the sleep is actually in the wrong location. > > > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > > > > > > > ret = max9271_configure_gmsl_link(&dev->serializer); > > > if (ret) > > > > > -- > Regards, > > Laurent Pinchart
diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c index babd14b21252..875bec9f7904 100644 --- a/drivers/media/i2c/rdacm21.c +++ b/drivers/media/i2c/rdacm21.c @@ -448,7 +448,10 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) if (ret) return ret; - /* Enable GPIO1 and hold OV490 in reset during max9271 configuration. */ + /* + * Enable GPIO1 and hold OV490 in reset during max9271 configuration. + * The reset signal has to be asserted for at least 250 useconds. + */ ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT); if (ret) return ret; @@ -456,6 +459,7 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val) ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT); if (ret) return ret; + usleep_range(250, 500); ret = max9271_configure_gmsl_link(&dev->serializer); if (ret)
Add a delay after the OV490 chip is put in reset state. The reset signal shall be held for at least 250 useconds. Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> --- drivers/media/i2c/rdacm21.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)