Re: [PATCH][next] media: i2c: ds90ub960: Fix missing return check on ub960_rxport_read call

[Tomi Valkeinen]

On 03/10/2024 16:19, Sakari Ailus wrote:
> Moi,
>
> On Thu, Oct 03, 2024 at 03:52:17PM +0300, Tomi Valkeinen wrote:
> > Hi,
> >
> > On 03/10/2024 09:05, Sakari Ailus wrote:
> > > Hi Colin,
> > >
> > > On Wed, Oct 02, 2024 at 05:53:29PM +0100, Colin Ian King wrote:
> > > > The function ub960_rxport_read is being called and afterwards ret is
> > > > being checked for any failures, however ret is not being assigned to
> > > > the return of the function call. Fix this by assigning ret to the
> > > > return of the call which appears to be missing.
> > > >
> > > > Fixes: afe267f2d368 ("media: i2c: add DS90UB960 driver")
> > > > Signed-off-by: Colin Ian King <colin.i.king@xxxxxxxxx>
> > > > ---
> > > >    drivers/media/i2c/ds90ub960.c | 2 +-
> > > >    1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/media/i2c/ds90ub960.c b/drivers/media/i2c/ds90ub960.c
> > > > index ffe5f25f8647..58424d8f72af 100644
> > > > --- a/drivers/media/i2c/ds90ub960.c
> > > > +++ b/drivers/media/i2c/ds90ub960.c
> > > > @@ -1286,7 +1286,7 @@ static int ub960_rxport_get_strobe_pos(struct ub960_data *priv,
> > > >    	clk_delay += v & UB960_IR_RX_ANA_STROBE_SET_CLK_DELAY_MASK;
> > > > -	ub960_rxport_read(priv, nport, UB960_RR_SFILTER_STS_1, &v);
> > > > +	ret = ub960_rxport_read(priv, nport, UB960_RR_SFILTER_STS_1, &v);
> > > >    	if (ret)
> > > >    		return ret;
> > >
> > > There seems to be a similar issues all around the driver. It'd be good to
> > > fix them at the same time.
> >
> > With similar issues, do you mean the code not checking the return value at
> > all for i2c reads and writes?
> >
> > In this particular case the code already checks the return value, but
> > setting the return value was missing. With a quick browse, I didn't see
> > other like this.
>
> See e.g. ub960_clear_rx_errors(), ub960_log_status(),
> ub960_rxport_set_strobe_pos() and ub960_rxport_set_strobe_range.

Right, those don't check the return value. So they're not the same as 
the one fixed in this patch.

I'm not arguing against adding error checks, but that's a big work and I 
think this patch is a different kind of fix which should be applied 
whether the additional error checks are added or not.

Also, while still not arguing against adding the checks, it looks quite 
common to not check the returns values. E.g. it's not just a few errors 
I see if I add __must_check to cci functions.

 Tomi