On Mon, Feb 24, 2025 at 03:03:40PM +0000, Aditya Garg wrote:
> > On 24 Feb 2025, at 8:27 PM, andriy.shevchenko@xxxxxxxxxxxxxxx wrote:
> > On Mon, Feb 24, 2025 at 02:32:37PM +0000, Aditya Garg wrote:
> >>> On 24 Feb 2025, at 7:30 PM, andriy.shevchenko@xxxxxxxxxxxxxxx wrote:
> >>> On Mon, Feb 24, 2025 at 01:40:20PM +0000, Aditya Garg wrote:
...
> >>>> +#define __APPLETBDRM_MSG_STR4(str4) ((__le32 __force)((str4[0] << 24) | (str4[1] << 16) | (str4[2] << 8) | str4[3]))
> >>>
> >>> As commented previously this is quite strange what's going on with endianess in
> >>> this driver. Especially the above weirdness when get_unaligned_be32() is being
> >>> open coded and force-cast to __le32.
> >>
> >> I would assume it was also mimicked from the Windows driver, though I haven't
> >> really tried exploring this there.
> >>
> >> I’d rather be happy if you give me code change suggestions and let me review
> >> and test them
> >
> > For the starter I would do the following for all related constants and
> > drop that weird and ugly macros at the top (it also has an issue with
> > the str4 length as it is 5 bytes long, not 4, btw):
> >
> > #define APPLETBDRM_MSG_CLEAR_DISPLAY cpu_to_le32(0x434c5244) /* CLRD */
>
> Lemme test this.
Just in case it won't work, reverse bytes in the integer. Because I was lost in
this conversion.
> > (assuming we stick with __leXX for now). This will be much less confusing.
...
> >> Alright. For some reason (a mistake on my part), some dev_err_probe were also
> >> still left in this version.
> >
> > But those are seems to me in the correct locations, no? How do we even know
> > the DRM device before its creation? So, dev_err_probe() calls in ->probe()
> > seem logical to me. Somebody from DRM should clarify this.
>
> Thomas asked me to do this change. Maybe you didn’t see his reply.
I saw, maybe I took it wrong, but I really don't understand how on earth
drm_err() or whatever can be used in real ->probe() of the physical device.
Imagine the hypotetical case
probe(strict device *dev)
{
mydrm;
foo;
...
foo = devm_gpiod_get(dev, ...);
if (IS_ERR(foo))
return dev_err_probe(dev, ...); // how?!
...
mydrm = ...DRM alloc...;
...
}
I don't even believe it will be possible to create drm_err_probe() as it most
likely will require to have an allocation to be always the first op (that may
fail) in the ->probe() which might be not the case for some device drivers.
> >>>> + */
--
With Best Regards,
Andy Shevchenko
