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authorLinas Vepstas <linas@austin.ibm.com>2007-04-11 06:11:23 +1000
committerPaul Mackerras <paulus@samba.org>2007-05-02 20:04:29 +1000
commit650f7b3b2f0ead0673e90452cf3dedde97c537ba (patch)
treee45e61e0bd0d39b18bef701e6d78e00e7c772bd6
parent8fce6dd29fa9d1ac880bf0cb4528e9bd5878cf68 (diff)
downloadlinux-650f7b3b2f0ead0673e90452cf3dedde97c537ba.tar.bz2
[POWERPC] pseries: Handle null iommu dma-window property correctly
Some versions of pSeries firmware fail to set up a dma-window property for PCI slots that are unoccupied. As a result, the loop searching for this propery, in pci_dma_dev_setup_pSeriesLP(), can run to the end, resulting in a NULL pointer dereference later in the routine. This patch prevents the crash, and prints a warning message. This is theoretically a rare error, as it occurs on what is hopefully just beta levels of firmware. But just in case this firmware escapes into the wild, this patch will avoid the crash. Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
-rw-r--r--arch/powerpc/platforms/pseries/iommu.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 66665c82415c..eec684a8e44e 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -504,6 +504,12 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
break;
}
+ if (!pdn || !PCI_DN(pdn)) {
+ printk(KERN_WARNING "pci_dma_dev_setup_pSeriesLP: "
+ "no DMA window found for pci dev=%s dn=%s\n",
+ pci_name(dev), dn? dn->full_name : "<null>");
+ return;
+ }
DBG(" parent is %s\n", pdn->full_name);
/* Check for parent == NULL so we don't try to setup the empty EADS