From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941554AbcJYGhG (ORCPT ); Tue, 25 Oct 2016 02:37:06 -0400 Received: from up.free-electrons.com ([163.172.77.33]:33716 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932674AbcJYGhE (ORCPT ); Tue, 25 Oct 2016 02:37:04 -0400 Date: Tue, 25 Oct 2016 08:37:00 +0200 From: Boris Brezillon To: Lukasz Majewski Cc: Thierry Reding , Stefan Agner , linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, Fabio Estevam , Fabio Estevam , Lothar Wassmann , Bhuvanchandra DV , kernel@pengutronix.de Subject: Re: [PATCH 6/6] pwm: imx: Introduce "polarity_supported" flag to PWMv2 driver Message-ID: <20161025083700.342f9abe@bbrezillon> In-Reply-To: <20161024231458.075ea50b@jawa> References: <1477259146-19167-1-git-send-email-l.majewski@majess.pl> <1477259146-19167-7-git-send-email-l.majewski@majess.pl> <20161024172852.40662611@bbrezillon> <20161024173410.6e641b9c@bbrezillon> <20161024231458.075ea50b@jawa> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lukasz, On Mon, 24 Oct 2016 23:14:58 +0200 Lukasz Majewski wrote: > Hi Boris, > > > On Mon, 24 Oct 2016 17:28:52 +0200 > > Boris Brezillon wrote: > > > > > On Sun, 23 Oct 2016 23:45:46 +0200 > > > Lukasz Majewski wrote: > > > > > > > The need for set_polarity() function has been removed by > > > > implementing PWM atomic support (apply() callback). > > > > > > > > To indicate that the PWMv2 supports polarity inversion, new flag - > > > > "polarity_supported" has been introduced. > > > > > > > > Signed-off-by: Lukasz Majewski > > > > --- > > > > drivers/pwm/pwm-imx.c | 4 +++- > > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > > > > index 02d3dfd..be3034d 100644 > > > > --- a/drivers/pwm/pwm-imx.c > > > > +++ b/drivers/pwm/pwm-imx.c > > > > @@ -258,6 +258,7 @@ static struct pwm_ops imx_pwm_ops_v2 = { > > > > }; > > > > > > > > struct imx_pwm_data { > > > > + bool polarity_supported; > > > > struct pwm_ops *pwm_ops; > > > > }; > > > > > > > > @@ -266,6 +267,7 @@ static struct imx_pwm_data imx_pwm_data_v1 = { > > > > }; > > > > > > > > static struct imx_pwm_data imx_pwm_data_v2 = { > > > > + .polarity_supported = true, > > > > .pwm_ops = &imx_pwm_ops_v2, > > > > }; > > > > > > > > @@ -313,7 +315,7 @@ static int imx_pwm_probe(struct > > > > platform_device *pdev) imx->chip.base = -1; > > > > imx->chip.npwm = 1; > > > > imx->chip.can_sleep = true; > > > > - if (data->pwm_ops->set_polarity) { > > > > + if (data->polarity_supported) { > > > > > > You're still breaking backward compatibility with DTs defining > > > #pwm-cells = 2. > > > > > > Please test the #pwm-cells value before deciding which of_xlate > > > should be used. > > > > Nevermind, I didn't look at [1] and [2]. > > Yes, some patches are required to make this code work. Especially, I > wanted to explicitly reuse and credit work already done by > Bhuvanchandra. > > > But still, your series is not bisectable: this change should be part > > of patch 5 where you remove the ->set_polarity implementation. > > Otherwise, this means you don't support polarity setting between > > patch 5 and 6. > > Frankly speaking, I did it on purpose, to have operations in commits > logically separated. > > I personally, do detest commits which blur the picture and are not > corresponding to one single logical change - for example remove some > large chunk of code and also add some tiny, new flag. > > For me it is not a problem to have polarity disabled between patches 5 > and 6, since at the end of the day we have it enabled. It's really simple to make this series bisectable, all you have to do is move patch 6 before patch 5. This being said, I really think you should follow Stefan's recommendation: base your changes on mainline and switch to the atomic hook before supporting polarity setting. Regards, Boris