On Mon, Sep 16, 2019 at 09:24:26PM +0200, Christophe JAILLET wrote:
> Le 16/09/2019 à 08:28, Dan Carpenter a écrit :
> > On Fri, Sep 13, 2019 at 09:57:09AM +0200, Maxime Ripard wrote:
> > > Hi Christophe,
> > >
> > > On Thu, Sep 12, 2019 at 10:44:50PM +0200, Christophe JAILLET wrote:
> > > > The 2nd parameter of 'find_first_zero_bit()' is a number of bits, not of
> > > > bytes. So use 'BITS_PER_LONG' instead of 'sizeof(lanes_used)'.
> > > >
> > > > Fixes: 1fc3b37f34f6 ("media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver")
> > > > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> > > > ---
> > > > This patch is purely speculative. Using BITS_PER_LONG looks logical to me,
> > > > but I'm not 100% sure that it is what is expected here. 'csi2rx->max_lanes'
> > > > could also be a good candidate.
> > > Yeah, csi2rx->max_lanes would make more sense in that context. Could
> > > you resend a new version?
> > This is sort of unrelated, but for Smatch purposes the csi2rx->max_lanes
> > comes from the firmware in csi2rx_parse_dt() and it could be any u8
> > value.
>
> Hi Dan,
>
> not sure to follow you.
>
> csi2rx_probe()
> --> csi2rx_get_resources()
> --> ...
> dev_cfg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
> ...
> csi2rx->max_lanes = dev_cfg & 7;
> if (csi2rx->max_lanes > CSI2RX_LANES_MAX) {
> dev_err(&pdev->dev, "Invalid number of lanes: %u\n",
> csi2rx->max_lanes);
> return -EINVAL;
> }
>
> So I guess, that we can trust max_lanes because of the 'if (... >
> CSI2RX_LANES_MAX)' check.
>
> Did I miss something?
Ugh... I was looking at ->num_lanes and I was also just totally wrong.
Smatch parses that badly. Smatch actually parses ->max_lanes correctly
though so that's ok.
Sorry for the noise on this.
regards,
dan carpenter
