Re: [PATCH v4 2/2] media: Add a driver for the ov7251 camera sensor
On 26.04.2018 15:04, Sakari Ailus wrote:
> 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, , 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.
Yes, thanks.
>
> + 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.ai...@iki.fi
>
--
Best regards,
Todor Tomov
Re: [PATCH v4 2/2] media: Add a driver for the ov7251 camera sensor
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, , 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.ai...@iki.fi
--
Sakari Ailus
e-mail: sakari.ai...@iki.fi
Re: [PATCH v4 2/2] media: Add a driver for the ov7251 camera sensor
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, , 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];
> >> + 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.ai...@iki.fi
Re: [PATCH v4 2/2] media: Add a driver for the ov7251 camera sensor
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, , 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];
>> +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 :)
>
>> +__func__, ret, reg);
>> +return ret;
>> +}
>> +
>> +return 0;
>> +}
>
--
Best regards,
Todor Tomov
Re: [PATCH v4 2/2] media: Add a driver for the ov7251 camera sensor
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, , 1);
And put the function below ov2751_write_seq_regs().
> +}
> +
> +static int ov7251_write_seq_regs(struct ov7251 *ov7251, u16 reg, u8 *val,
> + u8 num)
> +{
> + const u8 maxregbuf = 5;
> + u8 regbuf[maxregbuf];
> + 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...
If you're happy with these, I can make the changes, too; they're trivial.
> + __func__, ret, reg);
> + return ret;
> + }
> +
> + return 0;
> +}
--
Kind regards,
Sakari Ailus
e-mail: sakari.ai...@iki.fi
