netdev - [PATCH net 6/7] bnxt_en: Increase firmware message response DMA wait time

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Date:   Sun, 20 Feb 2022 04:05:52 -0500
From:   Michael Chan <michael.chan@...adcom.com>
To:     davem@...emloft.net
Cc:     netdev@...r.kernel.org, kuba@...nel.org, gospo@...adcom.com
Subject: [PATCH net 6/7] bnxt_en: Increase firmware message response DMA wait time

When polling for the firmware message response, we first poll for the
response message header.  Once the valid length is detected in the
header, we poll for the valid bit at the end of the message which
signals DMA completion.  Normally, this poll time for DMA completion
is extremely short (0 to a few usec).  But on some devices under some
rare conditions, it can be up to about 20 msec.

Increase this delay to 50 msec and use udelay() for the first 10 usec
for the common case, and usleep_range() beyond that.

Also, change the error message to include the above delay time when
printing the timeout value.

Fixes: 3c8c20db769c ("bnxt_en: move HWRM API implementation into separate file")
Reviewed-by: Vladimir Olovyannikov <vladimir.olovyannikov@...adcom.com>
Signed-off-by: Michael Chan <michael.chan@...adcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c | 12 +++++++++---
 drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.h |  2 +-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c
index 566c9487ef55..b01d42928a53 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.c
@@ -644,17 +644,23 @@ static int __hwrm_send(struct bnxt *bp, struct bnxt_hwrm_ctx *ctx)
 
 		/* Last byte of resp contains valid bit */
 		valid = ((u8 *)ctx->resp) + len - 1;
-		for (j = 0; j < HWRM_VALID_BIT_DELAY_USEC; j++) {
+		for (j = 0; j < HWRM_VALID_BIT_DELAY_USEC; ) {
 			/* make sure we read from updated DMA memory */
 			dma_rmb();
 			if (*valid)
 				break;
-			usleep_range(1, 5);
+			if (j < 10) {
+				udelay(1);
+				j++;
+			} else {
+				usleep_range(20, 30);
+				j += 20;
+			}
 		}
 
 		if (j >= HWRM_VALID_BIT_DELAY_USEC) {
 			hwrm_err(bp, ctx, "Error (timeout: %u) msg {0x%x 0x%x} len:%d v:%d\n",
-				 hwrm_total_timeout(i), req_type,
+				 hwrm_total_timeout(i) + j, req_type,
 				 le16_to_cpu(ctx->req->seq_id), len, *valid);
 			goto exit;
 		}
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.h
index d52bd2d63aec..c98032e38188 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_hwrm.h
@@ -90,7 +90,7 @@ static inline unsigned int hwrm_total_timeout(unsigned int n)
 }
 
 
-#define HWRM_VALID_BIT_DELAY_USEC	150
+#define HWRM_VALID_BIT_DELAY_USEC	50000
 
 static inline bool bnxt_cfa_hwrm_message(u16 req_type)
 {
-- 
2.18.1


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