Hi Martina,
On Fri, Dec 11, 2020 at 11:51:05AM -0000, Martina Krasteva wrote:
> Hi Sakari,
>
> > -----Original Message-----
> > From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > Sent: Friday, December 11, 2020 11:32 AM
> > To: Martina Krasteva <martinax.krasteva@xxxxxxxxxxxxxxx>
> > Cc: linux-media@xxxxxxxxxxxxxxx; mchehab@xxxxxxxxxx; robh+dt@xxxxxxxxxx;
> > devicetree@xxxxxxxxxxxxxxx; daniele.alessandrelli@xxxxxxxxxxxxxxx;
> > paul.j.murphy@xxxxxxxxxxxxxxx; gjorgjix.rosikopulos@xxxxxxxxxxxxxxx
> > Subject: Re: [PATCH v4 2/2] media: i2c: Add imx334 camera sensor driver
> >
> > Hi Martina,
> >
> > On Fri, Dec 11, 2020 at 10:56:33AM +0000, Martina Krasteva wrote:
> > ...
> > > +static int imx334_read_reg(struct imx334 *imx334, u16 reg, u32 len,
> > > +u32 *val) {
> > > + struct i2c_client *client = v4l2_get_subdevdata(&imx334->sd);
> > > + struct i2c_msg msgs[2] = { 0 };
> > > + u8 addr_buf[2] = { 0 };
> > > + u8 data_buf[4] = { 0 };
> > > + int ret;
> > > +
> > > + if (WARN_ON(len > 4))
> > > + return -EINVAL;
> > > +
> > > + put_unaligned_be16(reg, addr_buf);
> > > +
> > > + /* Write register address */
> > > + msgs[0].addr = client->addr;
> > > + msgs[0].flags = 0;
> > > + msgs[0].len = ARRAY_SIZE(addr_buf);
> > > + msgs[0].buf = addr_buf;
> > > +
> > > + /* Read data from register */
> > > + msgs[1].addr = client->addr;
> > > + msgs[1].flags = I2C_M_RD;
> > > + msgs[1].len = len;
> > > + msgs[1].buf = &data_buf[4 - len];
> > > +
> > > + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> > > + if (ret != ARRAY_SIZE(msgs))
> > > + return -EIO;
> > > +
> > > + *val = get_unaligned_le32(data_buf + (4 - len));
> >
> > Hmm. The device native endianness is big (on control interface) unless
> > something very unexpected happened in hardware development.
> >
> > You also can't do this as this will overrun data_buf.
>
> Imx334 uses little endian so I have to convert the values.
Ack. That's very unusual, and probably the first raw camera sensor
implemented that way.
Could you fix the data_buf overrun?
--
Sakari Ailus
