From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Eremin-Solenikov Subject: Re: [PATCH 02/15] GPIO: port LoCoMo gpio support from old driver Date: Fri, 31 Oct 2014 13:39:59 +0400 Message-ID: References: <1414454528-24240-1-git-send-email-dbaryshkov@gmail.com> <1414454528-24240-3-git-send-email-dbaryshkov@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Linux Input , "linux-leds-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org" , Andrea Adami , Russell King , Daniel Mack , Haojian Zhuang , Robert Jarzmik , Alexandre Courbot , Dmitry Torokhov , Bryan Wu , Richard Purdie , Samuel Ortiz , Lee Jones , Mark Brown , Jingoo To: Linus Walleij Return-path: In-Reply-To: Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: 2014-10-31 10:48 GMT+03:00 Linus Walleij : > On Tue, Oct 28, 2014 at 1:01 AM, Dmitry Eremin-Solenikov > wrote: > >> Add gpiolib driver for gpio pins placed on the LoCoMo GA. >> >> Signed-off-by: Dmitry Eremin-Solenikov > [skipped] > (etc, everywhere this pattern occurs). >> +static void locomo_gpio_set(struct gpio_chip *chip, >> + unsigned offset, int value) >> +{ >> + struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio); >> + unsigned long flags; >> + >> + spin_lock_irqsave(&lg->lock, flags); >> + >> + __locomo_gpio_set(chip, offset, value); >> + >> + spin_unlock_irqrestore(&lg->lock, flags); > > If you actually always have to be getting and releasing a spin lock around > the register writes, contemplate using regmap-mmio because that > is part of what it does. > > But is this locking really necessary? I have a custom of doing such locking and never having to think about somebody breaking into RMW cycles. Also isn't regmap an overkill here? Wouldn't regmap also do a lock/unlock around each register read/write/RMW? >> +static int locomo_gpio_remove(struct platform_device *pdev) >> +{ >> + struct locomo_gpio *lg = platform_get_drvdata(pdev); >> + int ret; >> + >> + ret = gpiochip_remove(&lg->gpio); >> + if (ret) { >> + dev_err(&pdev->dev, "Can't remove gpio chip: %d\n", ret); >> + return ret; >> + } > > The return value from gpiochip_remove() has been removed in v3.18-rc1 > so this will not compile. Yes, the fix will be in the next iteration. This patchset was based on 3.17 -- With best wishes Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html