Re: [PATCH] fakephp: Allocate PCI resources before adding the device

[Trent Piepho <xyzzy@speakeasy.org>]

On Fri, 28 Nov 2008, Rolf Eike Beer wrote:
> Trent Piepho wrote:
> > On Wed, 26 Nov 2008, Darrick J. Wong wrote:
> > > On Wed, Nov 26, 2008 at 03:55:35PM -0700, Alex Chiang wrote:
> > > > > Maybe it's different on powerpc then?  My pseudo-hotplugable device
> > > > > is also the only thing connected to the PCI-E host bus controller.
> > > > > At boot the controller is empty and so I think some code to enable
> > > > > its BARs gets skipped.  But without the pci_enable_device(), I get
> > > > > this:
> > > > >
> > > > > 01:00.0 Signal processing controller: Freescale Semiconductor Inc
> > > > > Aurora Nexus Trace Interface Flags: fast devsel, IRQ 255
> > > > >         Memory at 40000000 (64-bit, prefetchable) [disabled]
> > > > > [size=4K]
> > >
> > >                            Are you referring to this? ^^^^^^^^^^
> > >
> > > Without seeing the raw dump of the PCI config space, it looks to me like
> > > the memory space enable bit of the PCICMD register is unset.  Probably
> > > the device driver should call pci_enable_device() at init time, though I
> > > suppose you did say earlier that there is no driver.
> >
> > Yes, that's it.  It seems like since the BARs are normally enabled after a
> > device is scanned at boot time that they should also be enabled when a
> > device is found by a fakephp rescan.  So I thought it seemed reasonable to
> > put pci_enable_device() in fakephp.
>
> No, pci_enable_device() will be called by the device driver. The hotplug
> drivers have nothing to do with that.

I guess you didn't read the part about there not being a device driver?

Why should a device added by fakephp be configured differently than one
added at boot time?

Is there something that will break if fakephp enables devices it finds?