linux-kernel - Re: [PATCH v2 2/3] lib/vsprintf: Add support for generic FOURCCs by extending %p4cc

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Message-ID: <Z7xQikQeHLOHb1G8@smile.fi.intel.com>
Date: Mon, 24 Feb 2025 12:57:14 +0200
From: "andriy.shevchenko@...ux.intel.com" <andriy.shevchenko@...ux.intel.com>
To: Aditya Garg <gargaditya08@...e.com>
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Subject: Re: [PATCH v2 2/3] lib/vsprintf: Add support for generic FOURCCs by
 extending %p4cc

On Sun, Feb 23, 2025 at 03:16:28PM +0000, Aditya Garg wrote:

> > Looking at the header files, it looks like doing cpu_to_le32 on that variable and doing le32_to_cpu will actually reverse the order twice, on big endian systems, thus technically all way would not swap the order at all.
> > 
> > I'm not really sure how to manage the sparse warnings here.
> 
> Not sure whether the maintainers would like it, but we can do something like this:

This is not what we want, I believe. And this looks like a reinventing a wheel
of cpu_to_*() and *_to_cpu() or similar macros.

> 	case 'l’:
> #ifdef __LITTLE_ENDIAN
> 		val = orig;
> #else
> 		orig = swab32(orig);
> 		val = orig;
> #endif
> 		break;
> 
> 	case 'b’:
> #ifdef __LITTLE_ENDIAN
> 		orig = swab32(orig);
> 		val = orig;
> #else
> 		val = orig;
> #endif
> 		break;

-- 
With Best Regards,
Andy Shevchenko