From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756190AbeDYS6L (ORCPT ); Wed, 25 Apr 2018 14:58:11 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:35309 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755145AbeDYS6G (ORCPT ); Wed, 25 Apr 2018 14:58:06 -0400 X-Google-Smtp-Source: AIpwx4/lM61dhyeAO13M0WrdFWDE0Qro7mVKh3bYEbNTjbdQbGtv4+azI50TOvRLMkVdZdIX6Zs3Hg== Subject: Re: Lack of suspend/resume/shutdown ordering between GPIO providers and consumers To: Grygorii Strashko , linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, dmitry.torokhov@gmail.com, jeffy.chen@rock-chips.com, enric.balletbo@collabora.com, josephl@nvidia.com, opendmb@gmail.com, rjw@rjwysocki.net References: <03711276-d854-7f87-f2e2-c64716b09dbe@ti.com> <206bea0c-dbba-1bc3-d13b-dbc41d12c08b@gmail.com> From: Florian Fainelli Openpgp: preference=signencrypt Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata= xsDiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz80nRmxvcmlhbiBG YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+wmYEExECACYCGyMGCwkIBwMCBBUCCAME FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSDOw00ESM+4EhAQAL/o09boR9D3Vk1Tt7+gpYr3 WQ6hgYVON905q2ndEoA2J0dQxJNRw3snabHDDzQBAcqOvdi7YidfBVdKi0wxHhSuRBfuOppu pdXkb7zxuPQuSveCLqqZWRQ+Cc2QgF7SBqgznbe6Ngout5qXY5Dcagk9LqFNGhJQzUGHAsIs hap1f0B1PoUyUNeEInV98D8Xd/edM3mhO9nRpUXRK9Bvt4iEZUXGuVtZLT52nK6Wv2EZ1TiT OiqZlf1P+vxYLBx9eKmabPdm3yjalhY8yr1S1vL0gSA/C6W1o/TowdieF1rWN/MYHlkpyj9c Rpc281gAO0AP3V1G00YzBEdYyi0gaJbCEQnq8Vz1vDXFxHzyhgGz7umBsVKmYwZgA8DrrB0M oaP35wuGR3RJcaG30AnJpEDkBYHznI2apxdcuTPOHZyEilIRrBGzDwGtAhldzlBoBwE3Z3MY 31TOpACu1ZpNOMysZ6xiE35pWkwc0KYm4hJA5GFfmWSN6DniimW3pmdDIiw4Ifcx8b3mFrRO BbDIW13E51j9RjbO/nAaK9ndZ5LRO1B/8Fwat7bLzmsCiEXOJY7NNpIEpkoNoEUfCcZwmLrU +eOTPzaF6drw6ayewEi5yzPg3TAT6FV3oBsNg3xlwU0gPK3v6gYPX5w9+ovPZ1/qqNfOrbsE FRuiSVsZQ5s3AAMFD/9XjlnnVDh9GX/r/6hjmr4U9tEsM+VQXaVXqZuHKaSmojOLUCP/YVQo 7IiYaNssCS4FCPe4yrL4FJJfJAsbeyDykMN7wAnBcOkbZ9BPJPNCbqU6dowLOiy8AuTYQ48m vIyQ4Ijnb6GTrtxIUDQeOBNuQC/gyyx3nbL/lVlHbxr4tb6YkhkO6shjXhQh7nQb33FjGO4P WU11Nr9i/qoV8QCo12MQEo244RRA6VMud06y/E449rWZFSTwGqb0FS0seTcYNvxt8PB2izX+ HZA8SL54j479ubxhfuoTu5nXdtFYFj5Lj5x34LKPx7MpgAmj0H7SDhpFWF2FzcC1bjiW9mjW HaKaX23Awt97AqQZXegbfkJwX2Y53ufq8Np3e1542lh3/mpiGSilCsaTahEGrHK+lIusl6mz Joil+u3k01ofvJMK0ZdzGUZ/aPMZ16LofjFA+MNxWrZFrkYmiGdv+LG45zSlZyIvzSiG2lKy kuVag+IijCIom78P9jRtB1q1Q5lwZp2TLAJlz92DmFwBg1hyFzwDADjZ2nrDxKUiybXIgZp9 aU2d++ptEGCVJOfEW4qpWCCLPbOT7XBr+g/4H3qWbs3j/cDDq7LuVYIe+wchy/iXEJaQVeTC y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU8JPBBgRAgAPAhsMBQJU X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV HGuUuzv+GKZ6nsysJw== Message-ID: <7602f017-4abe-52ae-a112-7165076e2d89@gmail.com> Date: Wed, 25 Apr 2018 11:57:55 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/25/2018 11:47 AM, Grygorii Strashko wrote: > > > On 04/25/2018 01:29 PM, Florian Fainelli wrote: >> On 04/25/2018 11:06 AM, Grygorii Strashko wrote: >>> >>> >>> On 04/24/2018 05:58 PM, Florian Fainelli wrote: >>>> Hi Linus, Rafael, all >>>> >>>> Our GPIO controller driver: gpio-brcmstb.c has a shutdown callback >>>> which >>>> gets invoked when the system is brought into poweroff aka S5. So far so >>>> good, except that we also wish to use gpio_keys.c as a possible wake-up >>>> source, so we may have a number of GPIO pins declared as gpio-keys that >>>> allow the system to wake-up from deep slumber. >>>> >>>> Recently we noticed that we could easily get into a state where >>>> gpio-brcmstb.c::brcmstb_gpio_shutdown() gets called first, and then >>>> gpio_keys.c::gpio_keys_suspend() gets called later, which is too >>>> late to >>>> have the enable_irq_wake() call do anything sensible since we have >>>> suspend its parent interrupt controller before. This is completely >>>> expected unfortunately because these two drivers are both platform >>>> device instances with no connection to one another except via Device >>>> Tree and the use of the GPIOLIB APIs. >>> >>> You can take a look at device_link_add() and Co. >> >> OK, though that requires a struct device references, so while I could >> certainly resolve the device_node -> struct device that corresponds to >> the GPIO provider , that poses a number of issues: >> >> - not all struct device_node have a corresponding struct device >> reference (e.g: clock providers, interrupt controllers, and possibly >> other custom drivers), though in this case, they most likely do have one >> >> - resolving a struct device associated with a struct device_node is >> often done in a "bus" specific way, e.g: of_find_device_by_node(), so if >> the GPIO provider is e.g: i2c_device, pci_device etc. etc. this might >> not work that easily >> >> I think this is what Dmitry just indicated in his email as well. >> >>> >>> But it's little bit unclear what exactly you have issue with: >>> - shutdown >>> - suspend >>> >>> above are different (at least as it was before) and gpio-brcmstb.c >>>   brcmstb_gpio_shutdown() should not be called as part of suspend !? >>> may be you mean brcmstb_gpio_suspend? >> >> The issue exists with shutdown (through the use of "poweroff"), that is >> confirmed, but I cannot see how it does not exist with any suspend state >> as well, for the same reason that the ordering is not strictly enforced. > > Sry, but it still required some clarification :( - poweroff calls > device_shutdown() which, in turn, should not call .suspend(), so > how have you got both .shutdown() and .suspend() callbacks called during > poweroff? Am I missing smth? You are missing me telling you the whole story, sorry I got confused, but you are absolutely right these are separate lists and on poweroff/shutdown only ->shutdown() is called. What I had missed in the report I was submitted was that there was a .shutdown() callback being added to gpio_keys.c, which of course, because it's an Android based project is not in the upstream Linux kernel. The problem does remain valid though AFAICT. Thanks Grygorii! -- Florian