rsxx: Disallow discards from being unmapped.

This patch fixes a bug in which discards were always
calling pci_unmap_page. Discards should never call the
pci_unmap_page function call because they are never mapped.

This caused a race condition on PowerPC systems when issuing
discards, writes, and reads all at the same time. The
pci_map_page function would eventually map logical address
0 for a read or write. Discards are always assigned a DMA
address of 0 because they are never mapped. So if
pci_map_page mapped address 0 for a DMA and a discard was
"unmapped" then the address would be freed and would cause
an EEH event to occur when Hardware accesses the address.

This was injected/uncovered in commit:
b347f9cf0bc8d42ee95ba1d3837fd93045ab336b

The pci_dma_mapping_error function declares -1 a DMA_ERROR
not 0 like initially thought So before we would never unmap
discards because they were considered NULL.

This patch should fall on top of commit id:
fc1967bb08a6184ed44ef990e1dd4389901b809c

Also, the driver version is being up dated.

Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/block/rsxx/rsxx_priv.h b/drivers/block/rsxx/rsxx_priv.h
index 913740e53d3..23fa05630fe 100644
--- a/drivers/block/rsxx/rsxx_priv.h
+++ b/drivers/block/rsxx/rsxx_priv.h
@@ -52,7 +52,7 @@ struct proc_cmd;
 #define RS70_PCI_REV_SUPPORTED	4
 
 #define DRIVER_NAME "rsxx"
-#define DRIVER_VERSION "4.0.1.2498"
+#define DRIVER_VERSION "4.0.2.2510"
 
 /* Block size is 4096 */
 #define RSXX_HW_BLK_SHIFT		12