[lkml]   [2006]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: pci_restore_state
On Sun, 04 Jun 2006 06:13:30 -0400
Ryan Lortie <> wrote:

> Currently pci_restore_state() (drivers/pci/pci.c) restores the PCI state
> by copying in the saved PCI configuration space, a dword at a time,
> starting from 0 up to 15.
> This causes a crash when my Macbook resumes from sleep (specifically,
> when restoring the configuration space of the PCI bridge).
> Reading the PCI specification, the register at dword 1 (ie: bytes 4-7)
> is split half and half between status and command words. The command
> word effectively controls the way which the PCI device interacts with
> the system. If it is 0, the device is logically disconnected from the
> bus (PCI Local Bus Specification Revision 2.2, 6.2.2 "Device
> Control").
> When a device first powers up, the command register value is normally
> zero (and is zero in my specific case).
> The problem with the way that the PCI state is currently restored is
> that the write to the command register logically reconnects the device
> to the bus before the rest of the configuration space has been filled
> in.
> My Macbook crashes on resume.
> If I reverse the for loop to start from 15 and count down to 0, then the
> majority of the configuration space is filled in _before_ the command
> word is modified. No crash.

We have a patch pending which will do that.

The present plan will be to get this into 2.6.18.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-06-04 12:30    [W:0.049 / U:0.788 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site