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

[Aditya Garg]

> On 25 Feb 2025, at 4:17 PM, andriy.shevchenko at linux.intel.com wrote:
> 
> On Tue, Feb 25, 2025 at 10:36:03AM +0000, Aditya Garg wrote:
>>>> On 25 Feb 2025, at 4:03 PM, andriy.shevchenko at linux.intel.com 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.