From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
c770cb4cb505 ("PCI: Mark invalid BARs as unassigned") sets IORESOURCE_UNSET
if we fail to claim a resource. If we tried to claim a bridge window,
failed, clipped the window, and tried to claim the clipped window, we
failed again because of IORESOURCE_UNSET:
pci_bus 0000:00: root bus resource [mem 0xc0000000-0xffffffff window]
pci 0000:00:01.0: can't claim BAR 15 [mem 0xbdf00000-0xddefffff 64bit pref]: no compatible bridge window
pci 0000:00:01.0: [mem size 0x20000000 64bit pref] clipped to [mem size 0x1df00000 64bit pref]
pci 0000:00:01.0: bridge window [mem size 0x1df00000 64bit pref]
pci 0000:00:01.0: can't claim BAR 15 [mem size 0x1df00000 64bit pref]: no address assigned
The 00:01.0 window started as [mem 0xbdf00000-0xddefffff 64bit pref]. That
starts before the host bridge window [mem 0xc0000000-0xffffffff window], so
we clipped the 00:01.0 window to [mem 0xc0000000-0xddefffff 64bit pref].
But we left it marked IORESOURCE_UNSET, so the second claim failed when it
should have succeeded.
This means downstream devices will also fail for lack of resources, e.g.,
in the bugzilla below,
radeon 0000:01:00.0: Fatal error during GPU init
Clear IORESOURCE_UNSET when we clip a bridge window. Also clear
IORESOURCE_UNSET in our copy of the unclipped window so we can see exactly
what the original window was and how it now fits inside the upstream
window.
Fixes: c770cb4cb505 ("PCI: Mark invalid BARs as unassigned")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=85491#c47
Based-on-patch-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Based-on-patch-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Acked-by: Yinghai Lu <yinghai@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # 4.1+
---
drivers/pci/bus.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 6fbd3f2..d3346d2 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -256,6 +256,8 @@ bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
res->start = start;
res->end = end;
+ res->flags &= ~IORESOURCE_UNSET;
+ orig_res.flags &= ~IORESOURCE_UNSET;
dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
&orig_res, res);
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
