From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH v2] Input: silead - Do not try to directly access the GPIO when using ACPI pm Date: Thu, 2 Feb 2017 14:27:28 +0100 Message-ID: References: <20170122200008.27027-1-hdegoede@redhat.com> <20170122222015.GA31009@dtor-ws> <8a23b7b2-a7aa-d62d-947d-31301a0c92cc@redhat.com> <20170201174257.GE40045@dtor-ws> <20170202104130.GJ2053@lahna.fi.intel.com> <8e91084e-e0ea-b055-5c62-67a4e0e56df4@redhat.com> <20170202121018.GN2053@lahna.fi.intel.com> <20170202123206.GP2053@lahna.fi.intel.com> <20170202131251.GQ2053@lahna.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51678 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750933AbdBBN1b (ORCPT ); Thu, 2 Feb 2017 08:27:31 -0500 In-Reply-To: <20170202131251.GQ2053@lahna.fi.intel.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Mika Westerberg Cc: Dmitry Torokhov , "russianneuromancer @ ya . ru" , Gregor Riepl , linux-input@vger.kernel.org, Linus Walleij , Andy Shevchenko Hi, On 02-02-17 14:12, Mika Westerberg wrote: > On Thu, Feb 02, 2017 at 01:50:58PM +0100, Hans de Goede wrote: >> Hi, >> >> On 02-02-17 13:32, Mika Westerberg wrote: >>> On Thu, Feb 02, 2017 at 02:10:18PM +0200, Mika Westerberg wrote: >>>> I do not have a copy of the patch in this thread but sounds like >>>> something that might work. >>> >>> Actually, I seem have a copy of that patch. >>> >>> So you are saying that the device has a power GPIO in ACPI _CRS but it >>> should not be used for some reason? >> >> Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Setti >> { >> Name (WBUF, ResourceTemplate () >> { >> I2cSerialBusV2 (0x0040, ControllerInitiated, 0x00061A80, >> AddressingMode7Bit, "\\_SB.PCI0.I2C6", >> 0x00, ResourceConsumer, , Exclusive, >> ) >> GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestri >> "\\_SB.GPO1", 0x00, ResourceConsumer, , >> ) >> { // Pin list >> 0x0019 >> } >> GpioInt (Edge, ActiveHigh, Shared,// PullDefault, 0x0000, >> "\\_SB.GPO1", 0x00, ResourceConsumer, , >> ) >> { // Pin list >> 0x0013 >> } >> }) >> Return (WBUF) /* \_SB_.PCI0.I2C6.TCS4._CRS.WBUF */ >> } >> >> The setting of the special bit in the gpio control register leads to >> drivers/pinctrl/intel/pinctrl-cherryview.c chv_gpio_request_enable() >> returning -EBUSY, which in return makes gpiod_get_optional >> return -EBUSY for this pin, rather then NULL (as we would like). > > Actually what is wrong here is that your gpiod_get(dev, "power") falls > back to use plain indexes and returns the first GPIO even though it > should not as the driver specifically requests GPIO with name "power" > and there is no _DSD. There is no clear "binding" for this device in ACPI, so the fallback is actually used as a feature by the Silead driver (more or less), the use of "power" as name here is for the ARM + devicetree usage of the driver really, so IOW the series: > > Andy (Cc'd) has a patch that tries to make the fallback mechanism more > stricter which should in theory fix the problem as well. The patch > series is here: > > https://bitbucket.org/andy-shev/linux/commits/338c0226b631b8b497d143070a301d8b8883c349?at=master You are referring to might fix this, but then we may need to add an attempt to get the gpio by index for some boards which do not control it themselves from _PS#. I can give the linked series a try, but I would still like a fallback plan if we indeed encounter boards where we need to fallback to getting the gpio by index. Once we do that we're back to having the same problem as then we would do the same fallback on boards where the pin is reserved for _PS# usage, and end up with an -EBUSY error again. I guess we could ignore -EBUSY in the fallback path, or only do the fallback if acpi_bus_power_manageable() returns false. Regards, Hans