Re: [PATCH] media: dw9714: Fix powerup sequence
From: Sakari Ailus
Date: Fri Dec 19 2025 - 06:50:10 EST
Hi Ricardo,
On Mon, Dec 15, 2025 at 09:46:46AM +0100, Ricardo Ribalda wrote:
> Hi Hans
>
> On Wed, 10 Dec 2025 at 09:21, <johannes.goede@xxxxxxxxxxxxxxxx> wrote:
> >
> > Hi,
> >
> > On 10-Dec-25 8:53 AM, Ricardo Ribalda wrote:
> > > We have experienced seen multiple I2C errors while doing stress test on
> > > the module:
> > >
> > > dw9714 i2c-PRP0001:01: dw9714_vcm_resume I2C failure: -5
> > > dw9714 i2c-PRP0001:01: I2C write fail
> > >
> > > Inspecting the powerup sequence we found that it does not match the
> > > documentation at:
> > > https://blog.arducam.com/downloads/DW9714A-DONGWOON(Autofocus_motor_manual).pdf
> > >
> > > """
> > > (2) DW9714A requires waiting time of 12ms after power on. During this
> > > waiting time, the offset calibration of internal amplifier is
> > > operating for minimization of output offset current .
> > > """
> > >
> > > This patch increases the powerup delay to follow the documentation.
> > >
> > > Fixes: 9d00ccabfbb5 ("media: i2c: dw9714: Fix occasional probe errors")
> > > Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> >
> > Thanks, patch looks good to me:
> >
> > Reviewed-by: Hans de Goede <johannes.goede@xxxxxxxxxxxxxxxx>
>
> Some tags for the record
>
> Tested-by: Neil Sun <neil.sun@xxxxxxxxxxxxxxxxxx>
> Co-developed-by: Naomi Huang <naomi.huang@xxxxxxxxxxxxxxxxxx>
Thanks, I added Cc: stable while applying it.
--
Regards,
Sakari Ailus