On Tue, Aug 9, 2022 at 5:26 AM Luke Jones <luke@xxxxxxxxxx> wrote:
...
> >> + pr_err("This device has lid-flip-rog quirk
> >> but got ENODEV checking it. This is a bug.");
> >
> > dev_err() ?
>
> Okay, changed here and in previous patch to match it.
>
> So that I'm clearer on dev_err(), this doesn't do something like exit
> the module does it? It's just a more detailed error print?
Yes, it's more specific when the user sees it. The pr_err() is global
and anonymous (you can only point to the driver, and not the instance
of the device bound to it), while dev_err() is device specific and the
user will immediately see which device instance is failing. Yet it's
not a problem for this particular driver, because I don't believe one
may have two, but it's a good coding practice in general.
(Note the last sentence: "good coding practice")
...
> >> +static void lid_flip_rog_tablet_mode_get_state(struct asus_wmi
> >> *asus)
> >> +{
> >> + int result = asus_wmi_get_devstate_simple(asus,
> >> ASUS_WMI_DEVID_LID_FLIP_ROG);
> >> +
> >> + if (result >= 0) {
> >
> > First of all, it's better to decouple assignment and definition, and
> > move assignment closer to its user. This is usual pattern.
>
> I don't fully understand why you would want the separation given how
> short these two blocks are (I'll change in this and previous patch of
> course, I just don't personally understand it).
See above, "good coding practice". Why?
Imagine your code to be in hypothetical v5.10:
int x = foo(param1, param2, ...);
if (x)
return Y;
Now, at v5.12 somebody adds a new feature which touches your code:
int x = foo(param1, param2, ...);
struct bar *baz;
if (we_have_such_feature_disabled)
return Z;
if (x)
return Y;
baz = ...
And then somebody else in v5.13 does another feature:
int x = foo(param1, param2, ...);
struct bar *baz;
if (we_have_such_feature_disabled)
return Z;
/* parameter 1 can be NULL, check it */
if (!param1)
return -EINVAL;
if (x)
return Y;
baz = ...
Do you see now an issue? If you emulate this as a sequence of Git
changes the last one is easily missing subtle detail. That's why "good
coding practice".
--
With Best Regards,
Andy Shevchenko
