[TG3]: Fix nvram arbitration bugs.

The nvram arbitration rules were not strictly followed in a few places
and this could lead to reading corrupted values from the nvram.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 47bd4a394420..dabc39befd3c 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -8533,6 +8533,7 @@ static void __devinit tg3_nvram_init(struct tg3 *tp)
             GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701) {
                 tp->tg3_flags |= TG3_FLAG_NVRAM;
 
+                tg3_nvram_lock(tp);
                 tg3_enable_nvram_access(tp);
 
                 if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5752)
@@ -8543,6 +8544,7 @@ static void __devinit tg3_nvram_init(struct tg3 *tp)
                 tg3_get_nvram_size(tp);
 
                 tg3_disable_nvram_access(tp);
+                tg3_nvram_unlock(tp);
 
         } else {
                 tp->tg3_flags &= ~(TG3_FLAG_NVRAM | TG3_FLAG_NVRAM_BUFFERED);
@@ -8640,10 +8642,10 @@ static int tg3_nvram_read(struct tg3 *tp, u32 offset, u32 *val)
         if (ret == 0)
                 *val = swab32(tr32(NVRAM_RDDATA));
 
-        tg3_nvram_unlock(tp);
-
         tg3_disable_nvram_access(tp);
 
+        tg3_nvram_unlock(tp);
+
         return ret;
 }
 
@@ -8728,6 +8730,10 @@ static int tg3_nvram_write_block_unbuffered(struct tg3 *tp, u32 offset, u32 len,
 
                 offset = offset + (pagesize - page_off);
 
+                /* Nvram lock released by tg3_nvram_read() above,
+                 * so need to get it again.
+                 */
+                tg3_nvram_lock(tp);
                 tg3_enable_nvram_access(tp);
 
                 /*