Re: [PATCH v4 2/2] media: i2c: add ov2735 image sensor driver

From: Andy Shevchenko
Date: Thu Jul 17 2025 - 08:37:38 EST


On Thu, Jul 17, 2025 at 07:26:49AM +0000, Hardevsinh Palaniya wrote:
> > On Wed, Jul 16, 2025 at 07:14:17PM +0530, Hardevsinh Palaniya wrote:

...

> > > +static int ov2735_page_access(struct ov2735 *ov2735,
> > > +                           u32 reg, void *val, int *err, bool is_read)
> > > +{
> > > +     u8 page = (reg >> CCI_REG_PRIVATE_SHIFT) & 0xff;
> > > +     u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
> > > +     int ret = 0;
> > > +
> > > +     if (err && *err)
> > > +             return *err;
> > > +
> > > +     mutex_lock(&ov2735->page_lock);
> > > +
> > > +     /* Perform page access before read/write */
> > > +     if (ov2735->current_page != page) {
> > > +             ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, &ret);
> > > +             if (ret)
> > > +                     goto err_mutex_unlock;
> > > +             ov2735->current_page = page;
> > > +     }
> > > +
> > > +     if (is_read)
> > > +             ret = cci_read(ov2735->cci, addr, (u64 *)val, err);
> > > +     else
> > > +             ret = cci_write(ov2735->cci, addr, *(u64 *)val, err);
> > > +
> > > +err_mutex_unlock:
> >
> > > +     if (ret && err)
> >
> > Why do you need to check for ret != 0?
>
> To prevents overwriting *err with 0 on successful operations, which could
> obscure previous errors.

Can you elaborate a bit how the *err is not 0 at this point
(assuming err != NULL)?

--
With Best Regards,
Andy Shevchenko