Re: [PATCH v5] i2c: imx: support DMA defer probing

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Fri, Dec 20, 2024 at 05:59:38AM +0000, Carlos Song wrote:
> > > So we make this logic. Anyway we let the I2C controller registered whether
> > DMA is available or not(except defer probe).
> > > Ignoring ENODEV and EPROBE_DEFER makes it looks like nothing happened if
> > DMA is defer probed or not enabled(This is an expected).
> > > However we still need i2c DMA status is known when meet an unexpected
> > error, so we use dev_err_probe() to print error.
> >
> > Why dev_err_probe() instead of dev_err()?
> >
> Hi,
> In patch V2 discussion, Marc suggested just return dev_err_probe(), but I don't accept it so I choose to use dev_err_probe() to print error in V3.[1]
> In this case, the two APIs have the same function, do you mean dev_err() is more suitable?

Yes, dev_err_probe() should be used in combination with return. For
example:
  return dev_err_probe(...);

It will pass the return value on exit of the function and optionally
print of the error message if it is not EPROBE_DEFER. Practically it
replace commonly used coding pattern:
  if (ret == -EPROBE_DEFER) {
    return ret;
  } else if (ret) {
    dev_err(..);
    return ret;
  }

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