From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH 1/2] pinctrl: qcom: disable GPIO groups with no pins Date: Fri, 14 Jul 2017 15:04:22 -0700 Message-ID: <20170714220422.GM22780@codeaurora.org> References: <1499982763-29619-1-git-send-email-timur@codeaurora.org> <1499982763-29619-2-git-send-email-timur@codeaurora.org> <20170714171148.GH22780@codeaurora.org> <8eaeefc0-2f2c-a488-283f-80e26f4d13f5@codeaurora.org> <20170714214648.GL22780@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-arm-msm-owner@vger.kernel.org To: Timur Tabi Cc: andy.gross@linaro.org, david.brown@linaro.org, Linus Walleij , Bjorn Andersson , linux-gpio@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-gpio@vger.kernel.org On 07/14, Timur Tabi wrote: > On 07/14/2017 04:46 PM, Stephen Boyd wrote: > >Right, the gpiolib core would need to be updated to request the > >gpio in gpiochip_add_data() around the loop where it goes and > >configures things. And it could ignore ones that it can't request > >there. > > __gpiod_request already calls chip->request(), so this would need to > be a temporary request. It seems a bit hackish, but I'll try it. Yeah, request, configure, free, in a loop. Unless someone is aware why we don't do that here. > > BTW, I noticed that __gpiod_free() does this: > > if (chip->free) { > spin_unlock_irqrestore(&gpio_lock, flags); > ---> might_sleep_if(chip->can_sleep); > chip->free(chip, gpio_chip_hwgpio(desc)); > spin_lock_irqsave(&gpio_lock, flags); > > > Should __gpiod_request() also call might_sleep_if()? > > if (chip->request) { > /* chip->request may sleep */ > spin_unlock_irqrestore(&gpio_lock, flags); > ---> missing call to might_sleep_if() here? > status = chip->request(chip, gpio_chip_hwgpio(desc)); > spin_lock_irqsave(&gpio_lock, flags); > Probably. Except we would have caught it earlier when it was requested? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project