On Thu, Apr 26, 2018 at 10:16:56AM +0300, Sakari Ailus wrote:
> On Thu, Apr 26, 2018 at 10:04:25AM +0300, Todor Tomov wrote:
> > Hi Sakari,
> >
> > On 26.04.2018 09:50, Sakari Ailus wrote:
> > > Hi Todor,
> > >
> > > On Wed, Apr 25, 2018 at 07:20:46PM +0300, Todor Tomov wrote:
> > > ...
> > >> +static int ov7251_write_reg(struct ov7251 *ov7251, u16 reg, u8 val)
> > >> +{
> > >> + u8 regbuf[3];
> > >> + int ret;
> > >> +
> > >> + regbuf[0] = reg >> 8;
> > >> + regbuf[1] = reg & 0xff;
> > >> + regbuf[2] = val;
> > >> +
> > >> + ret = i2c_master_send(ov7251->i2c_client, regbuf, 3);
> > >> + if (ret < 0) {
> > >> + dev_err(ov7251->dev, "%s: write reg error %d: reg=%x, val=%x\n",
> > >> + __func__, ret, reg, val);
> > >> + return ret;
> > >> + }
> > >> +
> > >> + return 0;
> > >
> > > How about:
> > >
> > > return ov7251_write_seq_regs(ov7251, reg, &val, 1);
> > >
> > > And put the function below ov2751_write_seq_regs().
> >
> > I'm not sure... It will calculate message length each time and then check
> > that it is not greater than 5, which it is. Seems redundant.
> >
> > >
> > >> +}
> > >> +
> > >> +static int ov7251_write_seq_regs(struct ov7251 *ov7251, u16 reg, u8 *val,
> > >> + u8 num)
> > >> +{
> > >> + const u8 maxregbuf = 5;
> > >> + u8 regbuf[maxregbuf];
Apparently this leads to bad positive sparse warning. I'd fix it by:
diff --git a/drivers/media/i2c/ov7251.c b/drivers/media/i2c/ov7251.c
index 3e2c0c03dfa9..d3ebb7529fca 100644
--- a/drivers/media/i2c/ov7251.c
+++ b/drivers/media/i2c/ov7251.c
@@ -643,12 +643,11 @@ static int ov7251_write_reg(struct ov7251 *ov7251, u16 reg, u8 val)
static int ov7251_write_seq_regs(struct ov7251 *ov7251, u16 reg, u8 *val,
u8 num)
{
- const u8 maxregbuf = 5;
- u8 regbuf[maxregbuf];
+ u8 regbuf[5];
u8 nregbuf = sizeof(reg) + num * sizeof(*val);
int ret = 0;
- if (nregbuf > maxregbuf)
+ if (nregbuf > sizeof(regbuf))
return -EINVAL;
regbuf[0] = reg >> 8;
Let me know if you're happy with that; I can merge it to the original
patch.
> > >> + u8 nregbuf = sizeof(reg) + num * sizeof(*val);
> > >> + int ret = 0;
> > >> +
> > >> + if (nregbuf > maxregbuf)
> > >> + return -EINVAL;
> > >> +
> > >> + regbuf[0] = reg >> 8;
> > >> + regbuf[1] = reg & 0xff;
> > >> +
> > >> + memcpy(regbuf + 2, val, num);
> > >> +
> > >> + ret = i2c_master_send(ov7251->i2c_client, regbuf, nregbuf);
> > >> + if (ret < 0) {
> > >> + dev_err(ov7251->dev, "%s: write seq regs error %d: first reg=%x\n",
> > >
> > > This line is over 80...
> >
> > Yes indeed. Somehow checkpatch does not report this line, I don't know why.
> >
> > >
> > > If you're happy with these, I can make the changes, too; they're trivial.
> >
> > Only the second one? Thanks :)
>
> Works for me. I'd still think the overhead of managing the buffer is
> irrelevant where to having an extra function to do essentially the same
> thing is a source of maintenance and review work. Note that we're even now
> spending time to discuss it. ;-)
>
> --
> Kind regards,
>
> Sakari Ailus
> e-mail: sakari.ailus@xxxxxx
--
Sakari Ailus
e-mail: sakari.ailus@xxxxxx
