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authorEdwin Peer <edwin.peer@broadcom.com>2021-08-29 03:35:00 -0400
committerDavid S. Miller <davem@davemloft.net>2021-08-30 09:35:04 +0100
commit02b9aa1068682319508f9a1678e993ad958a8a4f (patch)
tree2ae4109956e2c44b382dbc21199166e550e234e5 /drivers
parentf9ff578251dc2f1cf5b9b007e050033d8414829d (diff)
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bnxt_en: discard out of sequence HWRM responses
During firmware crash recovery, it is possible for firmware to respond to stale HWRM commands that have already timed out. Because response buffers may be reused, any out of sequence responses need to be ignored and only the matching seq_id should be accepted. Also, READ_ONCE should be used for the reads from the DMA buffer to ensure that the necessary loads are scheduled. Reviewed-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Edwin Peer <edwin.peer@broadcom.com> Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c21
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c
index a45f2a619086..621daf687a00 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c
@@ -399,9 +399,10 @@ static int __hwrm_send(struct bnxt *bp, struct bnxt_hwrm_ctx *ctx)
le16_to_cpu(ctx->req->req_type));
goto exit;
}
- len = le16_to_cpu(ctx->resp->resp_len);
+ len = le16_to_cpu(READ_ONCE(ctx->resp->resp_len));
valid = ((u8 *)ctx->resp) + len - 1;
} else {
+ __le16 seen_out_of_seq = ctx->req->seq_id; /* will never see */
int j;
/* Check if response len is updated */
@@ -411,9 +412,21 @@ static int __hwrm_send(struct bnxt *bp, struct bnxt_hwrm_ctx *ctx)
*/
if (test_bit(BNXT_STATE_FW_FATAL_COND, &bp->state))
goto exit;
- len = le16_to_cpu(ctx->resp->resp_len);
- if (len)
- break;
+ len = le16_to_cpu(READ_ONCE(ctx->resp->resp_len));
+ if (len) {
+ __le16 resp_seq = READ_ONCE(ctx->resp->seq_id);
+
+ if (resp_seq == ctx->req->seq_id)
+ break;
+ if (resp_seq != seen_out_of_seq) {
+ netdev_warn(bp->dev, "Discarding out of seq response: 0x%x for msg {0x%x 0x%x}\n",
+ le16_to_cpu(resp_seq),
+ le16_to_cpu(ctx->req->req_type),
+ le16_to_cpu(ctx->req->seq_id));
+ seen_out_of_seq = resp_seq;
+ }
+ }
+
/* on first few passes, just barely sleep */
if (i < HWRM_SHORT_TIMEOUT_COUNTER) {
usleep_range(HWRM_SHORT_MIN_TIMEOUT,