Re: [RESEND PATCH v7 2/2] media: dw9807: Add dw9807 vcm driver

[Tomasz Figa <tfiga@chromium.org>]

On Wed, Apr 11, 2018 at 1:38 PM Tomasz Figa <tfiga@chromium.org> wrote:
[snip]
> > +static int dw9807_set_dac(struct i2c_client *client, u16 data)
> > +{
> > +       const char tx_data[3] = {
> > +               DW9807_MSB_ADDR, ((data >> 8) & 0x03), (data & 0xff)
> > +       };
> > +       int ret, retry = 0;
> > +
> > +       /*
> > +        * According to the datasheet, need to check the bus status
> before we
> > +        * write VCM position. This ensure that we really write the
value
> > +        * into the register
> > +        */
> > +       while ((ret = dw9807_i2c_check(client)) != 0) {
> > +               if (ret < 0)
> > +                       return ret;
> > +
> > +               if (MAX_RETRY == ++retry) {
> > +                       dev_err(&client->dev,
> > +                               "Cannot do the write operation because
> VCM is busy\n");
> > +                       return -EIO;
> > +               }
> > +               usleep_range(DW9807_CTRL_DELAY_US, DW9807_CTRL_DELAY_US
+
> 10);
> > +       }

> One could use readx_poll_timeout() here:

> int val;

> ret = readx_poll_timeout(dw9807_i2c_check, client, val, !val,

Actually, to handle errors, it should be

ret = readx_poll_timeout(dw9807_i2c_check, client, val, val <= 0,

>                            DW9807_CTRL_DELAY_US,
>                            MAX_RETRY * DW9807_CTRL_DELAY_US);

> if (ret) {

if (ret || val < 0) {

>           dev_err(&client->dev,
>                   "Cannot do the write operation because VCM is busy\n");
>           return -EIO;

return ret ? ret : val;

Sorry for not spotting this earlier.

Best regards,
Tomasz