For 64-bit BAR[i] only pci_dev->resource[i] is valid, ->resource[i+1]
slot is unused and contains zeroes in all fields.
So when we update a PCI BAR, all we need is just to check that we're
going to update a _valid_ resource.
Also make sure to write high bits - use "x >> 16 >> 16" (rather than the
simpler ">> 32") to avoid warnings on 32-bit architectures where we're
not going to have any high bits.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some PCI devices (e.g. 3c905B, 3c556B) lose all configuration
(including BARs) when transitioning from D3hot->D0. This leaves such
a device in an inaccessible state. The patch below causes the BARs
to be restored when enabling such a device, so that its driver will
be able to access it.
The patch also adds pci_restore_bars as a new global symbol, and adds a
correpsonding EXPORT_SYMBOL_GPL for that.
Some firmware (e.g. Thinkpad T21) leaves devices in D3hot after a
(re)boot. Most drivers call pci_enable_device very early, so devices
left in D3hot that lose configuration during the D3hot->D0 transition
will be inaccessible to their drivers.
Drivers could be modified to account for this, but it would
be difficult to know which drivers need modification. This is
especially true since often many devices are covered by the same
driver. It likely would be necessary to replicate code across dozens
of drivers.
The patch below should trigger only when transitioning from D3hot->D0
(or at boot), and only for devices that have the "no soft reset" bit
cleared in the PM control register. I believe it is safe to include
this patch as part of the PCI infrastructure.
The cleanest implementation of pci_restore_bars was to call
pci_update_resource. Unfortunately, that does not currently exist
for the sparc64 architecture. The patch below includes a null
implemenation of pci_update_resource for sparc64.
Some have expressed interest in making general use of the the
pci_restore_bars function, so that has been exported to GPL licensed
modules.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Ivan Kokshaysky