> On 24 Feb 2025, at 9:08 PM, andriy.shevchenko@xxxxxxxxxxxxxxx wrote: > > On Mon, Feb 24, 2025 at 03:32:56PM +0000, Aditya Garg wrote: >>> On 24 Feb 2025, at 8:50 PM, Aditya Garg <gargaditya08@xxxxxxxx> wrote: >>>> On 24 Feb 2025, at 8:41 PM, andriy.shevchenko@xxxxxxxxxxxxxxx wrote: >>>> 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. >>> >>> It works. What I understand is that you used the macro to get the final hex and converted it into little endian, which on the x86 macs would technically remain the same. >> >> And now that I oberved again, %p4cc is actually printing these CLRD, REDY etc >> in reverse order, probably the reason %p4ch was chosen. And I am unable to >> find what macro upstream can be used. > > %.4s should work as it technically not DRM 4cc, but specifics of the protocol > (that reminds me about ACPI that uses 4cc a lot). I still get reverse order in that. > > -- > With Best Regards, > Andy Shevchenko > >
