[PATCH v2 05/11] s390: pci: don't print uninitialized data for debugging

Arnd Bergmann arnd at arndb.de
Thu Nov 10 08:44:48 PST 2016

gcc correctly warns about an incorrect use of the 'pa' variable
in case we pass an empty scatterlist to __s390_dma_map_sg:

arch/s390/pci/pci_dma.c: In function '__s390_dma_map_sg':
arch/s390/pci/pci_dma.c:309:13: warning: 'pa' may be used uninitialized in this function [-Wmaybe-uninitialized]

This adds a bogus initialization to the function to sanitize
the debug output.  I would have preferred a solution without
the initialization, but I only got the report from the
kbuild bot after turning on the warning again, and didn't
manage to reproduce it myself.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Acked-by: Sebastian Ott <sebott at linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
 arch/s390/pci/pci_dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 7350c8b..6b2f72f 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -423,7 +423,7 @@ static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	dma_addr_t dma_addr_base, dma_addr;
 	int flags = ZPCI_PTE_VALID;
 	struct scatterlist *s;
-	unsigned long pa;
+	unsigned long pa = 0;
 	int ret;
 	size = PAGE_ALIGN(size);

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