From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Sat, 07 Aug 2010 09:58:52 +0000 Subject: Re: [PATCH 01/18] char: moxa: call disable_pci_device() if Message-Id: <20100807095852.GX9031@bicker> List-Id: References: <1281124152-12630-1-git-send-email-segooon@gmail.com> <20100807072205.GW9031@bicker> <20100807085512.GA5783@albatros> In-Reply-To: <20100807085512.GA5783@albatros> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vasiliy Kulikov Cc: kernel-janitors@vger.kernel.org, Greg Kroah-Hartman , Alan Cox , Andrew Morton , Rakib Mullick , Ben Hutchings , linux-kernel@vger.kernel.org On Sat, Aug 07, 2010 at 12:55:12PM +0400, Vasiliy Kulikov wrote: > On Sat, Aug 07, 2010 at 09:22 +0200, Dan Carpenter wrote: > > On Fri, Aug 06, 2010 at 11:49:10PM +0400, Kulikov Vasiliy wrote: > > > Driver should call disable_pci_device() if it returns from pci_probe() > > > with error. Also it must not be called if pci_request_region() fails as > > > it means that somebody uses device resources and rules the device. > > > > > > > I think we should disable it actually. The comments on > > pci_enable_device() and pci_disable_device() say that only the first and > > last callers actually enable and disable it. The others just increment > > or decrement a counter. > > See this thread: http://lkml.org/lkml/2005/2/13/82 > > Specifically this mail: > > Date Mon, 14 Feb 2005 14:51:26 -0500 > From Jeff Garzik <> > > ... > You also need to consider situations such as out-of-tree drivers > for the same hardware (might not use PCI API), and situations where you > have peer devices discovered and used (PCI API doesn't have "hey, > device is associated with , too" capability). > ... > > Searching for 'pci_disable_device() inurl:lkml' doesn't give me newer info > aboud this problem, so I think it's better to play safe. > That's ancient. That's a couple months before the start of git. git show v2.6.12:drivers/pci/pci.c In those days pci_enable/disable_device() were not nestable. These days we can just unwind normally so it's a big improvement. regards, dan carpenter