[openib-general] Re: [PATCH 9 of 20] ipath - char devices for diagnostics and lightweight subnet management

[Greg KH]

On Thu, Mar 09, 2006 at 08:41:36PM -0800, Bryan O'Sullivan wrote:
> On Thu, 2006-03-09 at 17:04 -0800, Greg KH wrote:
> 
> > > I don't expect this to be a practical problem.  We're planning to add
> > > hotplug support to the driver once we have some cycles free.
> > 
> > Ugh, that means it's never going to be there.
> > 
> > All new PCI drivers have the requirement that they work properly in
> > hotplug systems, as they should follow the PCI core api.  If not, odds
> > are they will not be accepted into the tree :(
> 
> Okay, maybe we're talking at cross purposes here.  We do follow the PCI
> core API.  We have a __devinit probe and __devexit remove routine, a
> MODULE_DEVICE_TABLE, the kernel generates hotplug events when a device
> is detected or the driver is unloaded, and so on.
> 
> I *assumed* that there was something more that we would need to do in
> order to support real hotplug of actual physical cards, but now that I
> look more closely, it doesn't appear that there is.  At least, there's
> nothing in Documentation/pci.txt or LDD3 that indicates to me that we
> ought to be doing more.
> 
> Am I missing something?

Nope, that's all that you need to do.  Your driver will be notified that
the device will be going away by calling the disconnect function.  So
great, nothing needs to be done :)

Oh, and you can test this out if you don't have a pci hotplug system by
using the fakephp driver and disconnecting your device that way.

thanks,

greg k-h