From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Schiller Subject: Re: [PATCH v2] net: phy: mdio-gpio: fix access that may sleep Date: Wed, 14 Nov 2018 08:43:49 +0100 Message-ID: <248deac95f412b925b0de44ead2ffec6@dev.tdt.de> References: <20181114061703.11026-1-ms@dev.tdt.de> <20181114063703.13379-1-ms@dev.tdt.de> <20181114070528.GD17052@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, f.fainelli@gmail.com, davem@davemloft.net To: Andrew Lunn Return-path: In-Reply-To: <20181114070528.GD17052@lunn.ch> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 2018-11-14 08:05, Andrew Lunn wrote: > On Wed, Nov 14, 2018 at 07:37:03AM +0100, Martin Schiller wrote: >> This commit re-enables support for slow GPIO pins. It was initially >> introduced by commit >> 2d6c9091ab7630dfcf34417c6683ce4764d7d40a >> and got lost by commit >> 7e5fbd1e0700f1bdb94508f84ec2aeb01eed7b12 > > Hi Martin > > Was it really lost? It looks like _cansleep() just adds an extra check > might_sleep_if(extra_checks), but it does not change any > functionality. Well, you are right, the functionality itself is not broken, but using the NON _cansleep() functions on GPIOs that have the cansleep flag set, this leads to a lot of kernel warnings/backtraces which makes the system in fact useless. Thats the WARN_ON() here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpio/gpiolib.c?h=v4.20-rc2#n2992 and here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpio/gpiolib.c?h=v4.20-rc2#n3304 > > So the change itself is O.K, i'm just not too sure about the commit > message. > > Andrew Hmm, ok. What would you suggest for a better commit message? I thought it would be helpful to know that this was already in there and got (inadvertently?) removed by another commit. Martin