linux-kernel - Re: [PATCH v23 3/4] pwm: Add support for RZ/G2L GPT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <hb7agtiqcuotiie646a2nzwg2cfwmahtgzzexxsf4tqu3rztf6@qqq2a7qkazh5>
Date: Fri, 21 Feb 2025 10:08:24 +0100
From: Uwe Kleine-König <ukleinek@...nel.org>
To: Biju Das <biju.das.jz@...renesas.com>
Cc: kernel test robot <lkp@...el.com>, 
	Philipp Zabel <p.zabel@...gutronix.de>, "oe-kbuild-all@...ts.linux.dev" <oe-kbuild-all@...ts.linux.dev>, 
	Geert Uytterhoeven <geert+renesas@...der.be>, Magnus Damm <magnus.damm@...il.com>, 
	"linux-pwm@...r.kernel.org" <linux-pwm@...r.kernel.org>, 
	"linux-renesas-soc@...r.kernel.org" <linux-renesas-soc@...r.kernel.org>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, 
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: Re: [PATCH v23 3/4] pwm: Add support for RZ/G2L GPT

Hello Biju,

On Thu, Jan 09, 2025 at 09:32:58AM +0000, Biju Das wrote:
> > On Wed, Jan 08, 2025 at 02:13:09PM +0000, Biju Das wrote:
> > > Please let me know, if there is any feedback for this patch series or
> > > any new API to be adapted in next kernel version which simplifies the code, So that I can send next
> > version.
> > 
> > I didn't look, but if you're ambitious you can convert your driver to the waveform callbacks.
> 
> Is it ok, after the acceptance of initial version, will switch to waveform callbacks to enable
> the users of GPT(Reason: lot of customers are using GPT for backlight for LCD panels)?
> 
> Please let me know.

I'd still accept your driver with the legacy callbacks, mostly because
your effort is already that old (which I consider my fault mostly).

> Is there any documentation available for waveform callback? What scenarios we can use
> Waveform callbacks compared to traditional one? 

There is no nice documentation available yet. The improvements include:

 - arbitrary offsets for the duty cycle, so the active phase doesn't
   need to be at the start or the end of a period any more
 - consumers can query the result of a configuration request (before and
   also after the request was issued).

Both are of little importance if your focus is mostly backlights.

Best regards
Uwe

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)