From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Thu, 27 Sep 2018 22:29:55 +0200 From: Thierry Reding Message-ID: <20180927202955.GA4184@ulmo> References: <20180806155129.cjcc7okmwtaujf43@pengutronix.de> <20180809113054.GH21639@ulmo> <20180809152329.s6othcezo4enj3xg@pengutronix.de> <20180820095221.fydcvtz7ppcymrta@pengutronix.de> <20180904203724.isth6bmytgvlal5e@pengutronix.de> <20180921160230.eeej4tbrkdfxwi7s@pengutronix.de> <20180927182607.7onqymk5cde522kr@pengutronix.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="AhhlLboLdkugWU4S" Content-Disposition: inline In-Reply-To: <20180927182607.7onqymk5cde522kr@pengutronix.de> Subject: Re: RFC: don't let drivers issue pwm_disable after pwm_config(pwm, 0, period) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-bounces@pengutronix.de Sender: "kernel" To: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= Cc: linux-pwm@vger.kernel.org, Gavin Schenk , kernel@pengutronix.de List-ID: --AhhlLboLdkugWU4S Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 27, 2018 at 08:26:07PM +0200, Uwe Kleine-K=C3=B6nig wrote: > Hello Thierry, >=20 > On Fri, Sep 21, 2018 at 06:02:30PM +0200, Uwe Kleine-K=C3=B6nig wrote: > > On Tue, Sep 04, 2018 at 10:37:24PM +0200, Uwe Kleine-K=C3=B6nig wrote: > > > On Mon, Aug 20, 2018 at 11:52:21AM +0200, Uwe Kleine-K=C3=B6nig wrote: > > > > On Thu, Aug 09, 2018 at 05:23:30PM +0200, Uwe Kleine-K=C3=B6nig wro= te: > > > > > On Thu, Aug 09, 2018 at 01:30:54PM +0200, Thierry Reding wrote: > > > > > > I don't see how you could make that work. In practically all ca= ses a > > > > > > pwm_disable() would have to be assumed to cause the pin level t= o become > > > > > > undefined. That makes it pretty much useless. > > > > >=20 > > > > > Right, that's what I want. pwm_disable() should make no guarantee= s about > > > > > the pin level. [...] > > > > > > > > > > > I agree that this is simpler and clearer. However it also signi= ficantly > > > > > > reduces the flexibility of the API, and I'm not sure that it is= enough. > > > > > > Again, yes, for many cases this is sufficient, but it doesn't f= ully > > > > > > expose the capabilities of hardware. > > > > >=20 > > > > > Can you show me a use case that isn't possible to express with the > > > > > suggested change in semantic? > > > >=20 > > > > To get forward here the only missing points are: > > > >=20 > > > > a) Your claim that this simplification looses expressive power. > > > > b) Actually convert the users (assuming a) can be resolved) > > > >=20 > > > > I cannot find a usecase that cannot be handled with the suggested c= hange > > > > in semantic. So can I lure you in explaining what setup you have in > > > > mind? > > >=20 > > > I'd really like to get forward here, so you feedback would be very > > > welcome. What is the use case you have in mind when writing "it also > > > significantly reduces the flexibility of the API, and I'm not sure th= at > > > it is enough"? > >=20 > > I'm a bit irritated that you don't continue to communicate here. On > > August 9 I had the impression that we can discuss this topic to an end. > > But as you stopped replying we unfortunately cannot :-| >=20 > Seeing you reply on other topics I wonder what is the problem here. Can > you at least quickly confirm that you received my mails? Confirming that I'm receiving your emails. Sorry, but I haven't found the necessary time to look at the details here any closer to continue the discussion in a meaningful way. I will hopefully get around to it within the next couple of days. Thierry --AhhlLboLdkugWU4S Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAlutPcEACgkQ3SOs138+ s6EYcRAAnt/4/Wv3JD/KXkv5cf92s8PxdebGvIC7SyVTkxW6Cfq8MzVpho/Yt1Ju g09YjvxDYZZcj+wWw4ybivGwobmOTKeJX94CPpQSd4yTUMZqC1F3osNGrjkMm7KV gZtmtj0/NruPoTW/ut+f/slOdO434PKKjf6Gf4RJCWaLItR007SaXzuC6/zadvUe PIq1bL1a6o+hyRBOplNePqBtM+1LAzx+c1xIWaYwsLysFtjN6khL57+y4u0ue7+R uXOv8Em5l+H7xFGBIO4ExN1dbZt0ooOO7bnZYOwTDc43ai4PDpr26eHdfesBWmEy FSt+9o8TsYF3bOf97844BUl704w+stxLXAcdBwLFLvtsTEdx+EJjAd05cpyOU56o bEU5SekTekBYTyW/uWP9XmTDf1ZkeZvby5PBczkZnHvqz4R9laOw2wWSiufklbGB DPNRfaABnODypo0DciReSbNUQcl+dPPpCW+PJfZOZgK1vPRRlBn8weuOOUbzPObE cACCBJvERU3oLCs5YFxhL38KMYFQMoPB/9oOgbfUfXesWEzy2KXt7MlmMhemVeg7 mjdrdIjQDxBAFSftHf7+y0ir1pdeZWuQpQC2IK7pI6OowQTiDfCvUVar3V2BBTPC om4graBHp7NQ+XNFpDOx2hWbfs1s600LfV+AVr4PBzCbazx6BrI= =orBA -----END PGP SIGNATURE----- --AhhlLboLdkugWU4S--