On Wednesday, July 14, 2010 11:02:03 am Ben Greear wrote:The mrst logic introduced in 2.6.33-rc8 in commit
a712ffbc199849364c46e9112b93b66de08e2c26 causes boot
to hang on at least this platform:
Intel E5405 CPU
System Information
Manufacturer: Supermicro
Product Name: X7DBU
The cause of the hang is that pci_cap points to itself
as the next capability, putting the fixed_bar_cap into
an endless loop.
This patch detects the loop, prints a warning, and
continues on with useful work. This strategy was
suggested by Robert Hancock<hancockrwd@xxxxxxxxx>
This should be a candidate for 2.6.34.y as well.
Signed-off-by: Ben Greear<greearb@xxxxxxxxxxxxxxx>
---
:100644 100644 1cdc02c... 9535ba9... M arch/x86/pci/mrst.c
arch/x86/pci/mrst.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/arch/x86/pci/mrst.c b/arch/x86/pci/mrst.c
index 1cdc02c..9535ba9 100644
--- a/arch/x86/pci/mrst.c
+++ b/arch/x86/pci/mrst.c
@@ -76,6 +76,17 @@ static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn)
return pos;
}
+ if ((pcie_cap>> 20) == 0)
+ break;
+
+ if ((pcie_cap>> 20)<= pos) {
+ printk(KERN_WARNING "WARNING: mrst: detected loop"
+ " when searching for fixed BAR cap, previous"
+ " position: 0x%x new position: 0x%x"
+ " bus-number: %i devfn: %i\n",
+ pos, pcie_cap>> 20, bus->number, devfn);
Can you use dev_warn() here to print the device info in the
standard way?