Re: [PATCH v4 1/6] drm/format-helper: Add drm_fb_xrgb8888_to_gray8_line()

[Javier Martinez Canillas]

Hello Jani,

On 2/11/22 13:05, Jani Nikula wrote:

[snip]

>>>> I don't see why a while loop would be an improvement here TBH.
>>>
>>> Less letters to parse when reading the code.
>>
>> It's a simple refactoring of code that has worked well so far. Let's 
>> leave it as-is for now.
> 
> IMO *always* prefer a for loop over while or do-while.
> 
> The for (i = 0; i < N; i++) is such a strong paradigm in C. You
> instantly know how many times you're going to loop, at a glance. Not so
> with with the alternatives, which should be used sparingly.
> 
> And yes, the do-while suggested above is buggy, and you actually need to
> stop and think to see why.
>

Absolutely agree.

These format conversion helpers are not trivial to read and understand (at
least for me). In my opinion the code should be written in a way that ease
readability and make as robust and less error prone as possible.
 
> 
> BR,
> Jani.
Best regards,
-- 
Javier Martinez Canillas
Linux Engineering
Red Hat