From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linas Vepstas Date: Wed, 29 Jun 2005 23:00:19 +0000 Subject: Re: How to find hotplug slot of PCI dev? Message-Id: <20050629230019.GP28499@austin.ibm.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org On Wed, Jun 29, 2005 at 03:44:38PM -0700, Greg KH was heard to remark: > On Wed, Jun 29, 2005 at 05:05:08PM -0500, Linas Vepstas wrote: > > > > Hi, > > > > I can't think of any easy way of (generically) finding the pointer to > > struct hotplug_slot if I have a pointer to struct pci_dev in hand. > > There is no way, sorry. Remember, multiple pci_dev can point to a > single hotplug slot. Right. I have I pointer to a pci_dev. I want to find the pointer to the hotplug slot its in. > > I am sorely tempted to write a generic patch to > > drivers/pci/hotplug/pci_hotplug_core.c to add this support > > (getting it from each of the hotplug arch'es). Should I? > > If I submit sucha patch, would it get rejected out of hand > > as a bad idea? > > > > I need this for the generic fallback PCI error recovery support; > > Why? I don't understand the question... Because after discussions on the LKML, everyone decided that this code should be written in as generic a way as possible, rather than arch-dependent, because there will soon be a variety of PCI chipsets that will be able to detect PCI errors. > > I have a pointer to the device; if its in a hotplug slot, > > I want to toggle power to it. > > No you do not. That's a userspace policy, not something the kernel > should do. Argh. I thought we've run around the table a few times on this issue already. It is impossible for userspace to recover from PCI errors. The canonical example is the failure of a disk system underneath a block device. All other bus errors are handled in the device drivers; for example, scsi errors are handled by scsi drivers and/or scsi-generic code. fiber-channel errors are handled by the fiber channel controllers. Ethernet hangs are handled by ethernet watchdogs in each ethernet driver. I think its unrealistic at this point to try to turn PCI error recovery into a userspace policy. --linas ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_idt77&alloc_id492&op=click _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel