[PATCH] EDAC: e752x byte access fix

The reading of the DRA registers should be a byte at a time (one register at a
time) instead of 4 bytes at a time (four registers).  Reading a dword at a
time retrieves erroneous information from all but the first register.  A
change was made to read in each register in a loop prior to using the data in
those registers.

Signed-off-by: Brian Pomerantz <bapper@mvista.com>
Signed-off-by: Dave Jiang <djiang@mvista.com>
Signed-off-by: Doug Thompson <norsk5@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/edac/e752x_edac.c b/drivers/edac/e752x_edac.c
index ab9873924f4f..9abfc0dc3bae 100644
--- a/drivers/edac/e752x_edac.c
+++ b/drivers/edac/e752x_edac.c
@@ -782,7 +782,12 @@ static void e752x_init_csrows(struct mem_ctl_info *mci, struct pci_dev *pdev,
         u8 value;
         u32 dra, drc, cumul_size;
 
-        pci_read_config_dword(pdev, E752X_DRA, &dra);
+        dra = 0;
+        for (index=0; index < 4; index++) {
+                u8 dra_reg;
+                pci_read_config_byte(pdev, E752X_DRA+index, &dra_reg);
+                dra |= dra_reg << (index * 8);
+        }
         pci_read_config_dword(pdev, E752X_DRC, &drc);
         drc_chan = dual_channel_active(ddrcsr);
         drc_drbg = drc_chan + 1;  /* 128 in dual mode, 64 in single */