Re: [PATCH v5 2/2] drm/tiny: add driver for Apple Touch Bars in x86 Macs

[Thomas Zimmermann]

Hi

Am 25.02.25 um 12:01 schrieb andriy.shevchenko@xxxxxxxxxxxxxxx:
> On Tue, Feb 25, 2025 at 10:48:53AM +0000, Aditya Garg wrote:
> > > On 25 Feb 2025, at 4:17 PM, andriy.shevchenko@xxxxxxxxxxxxxxx wrote:
> > > On Tue, Feb 25, 2025 at 10:36:03AM +0000, Aditya Garg wrote:
> > > > > > On 25 Feb 2025, at 4:03 PM, andriy.shevchenko@xxxxxxxxxxxxxxx wrote:
> > > > > On Tue, Feb 25, 2025 at 10:09:42AM +0000, Aditya Garg wrote:
> ...
>
> > > > > > +static int appletbdrm_probe(struct usb_interface *intf,
> > > > > > +                const struct usb_device_id *id)
> > > > > > +{
> > > > > > +    struct usb_endpoint_descriptor *bulk_in, *bulk_out;
> > > > > > +    struct device *dev = &intf->dev;
> > > > > > +    struct appletbdrm_device *adev;
> > > > > > +    struct drm_device *drm;
> > > > > > +    int ret;
> > > > > > +
> > > > > > +    ret = usb_find_common_endpoints(intf->cur_altsetting, &bulk_in, &bulk_out, NULL, NULL);
> > > > > > +    if (ret) {
> > > > > > +        drm_err(drm, "Failed to find bulk endpoints\n");
> > > > > This is simply wrong (and in this case even lead to crash in some circumstances).
> > > > > drm_err() may not be used here. That's my point in previous discussions.
> > > > > Independently on the subsystem the ->probe() for the sake of consistency and
> > > > > being informative should only rely on struct device *dev,
> > > > I'm not sure how drm_err works,
> > > It's a macro.
> > >
> > > > but struct drm_device does have a struct device *dev as well.
> > > Yes, but only when it's initialized.
> > >
> > > > Anyways, this is something I'll leave for Thomas to reply.
> > > The code above is wrong independently on his reply :-)
> > I'm kinda stuck between contrasting views of 2 kernel maintainers lol,
> > so I said let Thomas reply.
> Sure. I also want him to clarify my question about potential drm_err_probe().

These threads get a little lengthy. What is the question?

Best regards
Thomas

>

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)