Re: [PATCH 3/4] pwm: Mark free pwm IDs as used in alloc_pwms()

From: Andy Shevchenko
Date: Wed Nov 16 2022 - 03:17:27 EST


On Tue, Nov 15, 2022 at 10:15:14PM +0100, Uwe Kleine-König wrote:
> alloc_pwms() only identified a free range of IDs and this range was marked
> as used only later by pwmchip_add(). Instead let alloc_pwms() already do
> the marking (which makes the function actually allocating the range and so
> justifies the function name). This way access to the allocated_pwms
> bitfield is limited to two functions only.

This change is a bit fragile in a long term. Currently we know that we have
no points of error after alloc_pwms() in ->probe(), but if somebody misses
this in the future, we became to the case where bitmap might be exhausted
(kinda resource leakage).

--
With Best Regards,
Andy Shevchenko