On Fri, 30 Jul 2010, Eric W. Biederman wrote: > "H. Peter Anvin" <hpa at zytor.com> writes: > > > On 07/30/2010 09:30 AM, Eric W. Biederman wrote: > >> > >>>> That said it looks like the code to do the shutdown is in > >>>> qla2x00_remove_one so it should be too hard if someone cared to > >>>> extract just the hardware bits. > >>> > >>> Charming. Code is there, just not hooked up. > >> > >> Using the .remove method in reboot is a fight a lost long ago. > >> > > > > Could you elucidate, please? > > My original proposal was for device_shutdown to call the .remove > methods as those are well exercised and tested in development. aka > rmmod. > > It was argued (with some merit) that for a system reboot we don't want > to perform all of the subsystem registration work, to make it more > likely that reboot -f will reboot even if there is a kernel oops. > > What I proposed and unfortunately failed to write the patch for at the > time is was to have the device remove path call shutdown before calling > remove, so drivers wouldn't have to code it all up twice. > > A lot of the disk drivers implement .shutdown these days and there aren't > may bug reports about kexec failing. So I would be reluctant to change > things other than on a driver by driver basis unless I had a lot of time > for testing etc. > > It might be worth playing with adding a pci_clear_master in > pci_device_shutdown. It has the potential to break things like usb > keyboards, so I would be careful. If it doesn't break fundamental > things like usb a pci_clear_master when shutting down devices should > improve reliability somewhat. > > And of course there is the old staple of work arounds: "rmmod <driver>" > before calling kexec --exec. Looking through all these emails, what's the upshot here? Is the expectation, for all storage drivers to starting to implement some 'minimal' level of shutdown with the hardware/firmware during the .shutdown callback? -- Andrew Vasquez
