From 650f7b3b2f0ead0673e90452cf3dedde97c537ba Mon Sep 17 00:00:00 2001 From: Linas Vepstas Date: Wed, 11 Apr 2007 06:11:23 +1000 Subject: [PATCH] [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 --- arch/powerpc/platforms/pseries/iommu.c | 6 ++++++ 1 file changed, 6 insertions(+) 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 : ""); + return; + } DBG(" parent is %s\n", pdn->full_name); /* Check for parent == NULL so we don't try to setup the empty EADS