From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Date: Mon, 12 Oct 2015 15:19:31 +0000 Subject: Re: [PATCH v2] backlight: pwm: reject legacy pwm request for device defined in dt Message-Id: <20151012171931.3fb922d2@bbrezillon> List-Id: References: <1444652943-19712-1-git-send-email-vladimir_zapolskiy@mentor.com> <561BB2BC.9090907@atmel.com> <20151012153029.62f948d2@bbrezillon> <561BBB9F.6060808@mentor.com> <20151012160608.41f04553@bbrezillon> <561BC177.2050000@mentor.com> In-Reply-To: <561BC177.2050000@mentor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vladimir Zapolskiy Cc: Nicolas Ferre , Thierry Reding , Lee Jones , Jingoo Han , Robert Jarzmik , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org On Mon, 12 Oct 2015 17:19:35 +0300 Vladimir Zapolskiy wrote: > > > Thierry's patch makes sure that EPROBE_DEFER is not returned when the > > PWM device definition is not found using in the PWM lookup tables or > > the DT definition, > > This is okay, but I'm interested in proper handling of cases other than > EPROBE_DEFER. EPROBE_DEFER and the related issues are on your balance > and I'm attempting to avoid interfering with it here :) I keep thinking we should fix all platforms using the ->pwm_id pdata field to attach a PWM device to a PWM backlight instead of trying to guess when falling back to the legacy API is acceptable... > > > and in this case the pwm_bl code will fallback to > > the legacy PWM API, which AFAICT is what you're trying to solve. > > Fallback must happen exclusively under (IS_ERR(pb->pwm) && > PTR_ERR(pb->pwm) != -EPROBE_DEFER && !pdev->dev.of_node) condition IMHO. > > Before EPROBE_DEFER appeared on the scene the condition was > (IS_ERR(pb->pwm) && !pdev->dev.of_node). > > So, the question is if my change requires any updates or not from your > point of view. ... but from a functional point of view your patch seems correct. Best Regards, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com