diff mbox series

[net,15/16] ionic: stretch heartbeat detection

Message ID 20220124185312.72646-16-snelson@pensando.io (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series ionic: updates for stable FW recovery | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 1 blamed authors not CCed: allenbh@pensando.io; 1 maintainers not CCed: allenbh@pensando.io
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 96 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Shannon Nelson Jan. 24, 2022, 6:53 p.m. UTC
The driver can be premature in detecting stalled firmware
when the heartbeat is not updated because the firmware can
occasionally take a long time (more than 2 seconds) to service
a request, and doesn't update the heartbeat during that time.

The firmware heartbeat is not necessarily a steady 1 second
periodic beat, but better described as something that should
progress at least once in every DECVMD_TIMEOUT period.
The single-threaded design in the FW means that if a devcmd
or adminq request launches a large internal job, it is stuck
waiting for that job to finish before it can get back to
updating the heartbeat.  Since all requests are "guaranteed"
to finish within the DEVCMD_TIMEOUT period, the driver needs
to less aggressive in checking the heartbeat progress.

We change our current 2 second window to something bigger than
DEVCMD_TIMEOUT which should take care of most of the issue.
We stop checking for the heartbeat while waiting for a request,
as long as we're still watching for the FW status.  Lastly,
we make sure our FW status is up to date before running a
devcmd request.

Once we do this, we need to not check the heartbeat on DEV
commands because it may be stalled while we're on the fw_down
path.  Instead, we can rely on the is_fw_running check.

Fixes: b2b9a8d7ed13 ("ionic: avoid races in ionic_heartbeat_check")
Signed-off-by: Brett Creeley <brett@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
---
 drivers/net/ethernet/pensando/ionic/ionic.h   |  2 +-
 .../net/ethernet/pensando/ionic/ionic_dev.c   |  6 ++--
 .../net/ethernet/pensando/ionic/ionic_lif.c   |  2 +-
 .../net/ethernet/pensando/ionic/ionic_main.c  | 34 ++++++++-----------
 4 files changed, 20 insertions(+), 24 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/pensando/ionic/ionic.h b/drivers/net/ethernet/pensando/ionic/ionic.h
index 04fdaf5c1a02..602f4d45d529 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic.h
@@ -18,7 +18,7 @@  struct ionic_lif;
 #define PCI_DEVICE_ID_PENSANDO_IONIC_ETH_PF	0x1002
 #define PCI_DEVICE_ID_PENSANDO_IONIC_ETH_VF	0x1003
 
-#define DEVCMD_TIMEOUT  10
+#define DEVCMD_TIMEOUT			5
 #define IONIC_ADMINQ_TIME_SLICE		msecs_to_jiffies(100)
 
 #define IONIC_PHC_UPDATE_NS	10000000000	    /* 10s in nanoseconds */
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.c b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
index 1535a40a5fab..51d36a549ef7 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
@@ -236,9 +236,11 @@  int ionic_heartbeat_check(struct ionic *ionic)
 	if (!idev->fw_status_ready)
 		return -ENXIO;
 
-	/* wait at least one watchdog period since the last heartbeat */
+	/* Because of some variability in the actual FW heartbeat, we
+	 * wait longer than the DEVCMD_TIMEOUT before checking again.
+	 */
 	last_check_time = idev->last_hb_time;
-	if (time_before(check_time, last_check_time + ionic->watchdog_period))
+	if (time_before(check_time, last_check_time + DEVCMD_TIMEOUT * 2 * HZ))
 		return 0;
 
 	fw_hb = ioread32(&idev->dev_info_regs->fw_heartbeat);
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index e84a01edc4e4..05dd8c4f5466 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -1787,7 +1787,7 @@  static void ionic_lif_quiesce(struct ionic_lif *lif)
 
 	err = ionic_adminq_post_wait(lif, &ctx);
 	if (err)
-		netdev_err(lif->netdev, "lif quiesce failed %d\n", err);
+		netdev_dbg(lif->netdev, "lif quiesce failed %d\n", err);
 }
 
 static void ionic_txrx_disable(struct ionic_lif *lif)
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_main.c b/drivers/net/ethernet/pensando/ionic/ionic_main.c
index 78771663808a..4029b4e021f8 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_main.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_main.c
@@ -358,13 +358,14 @@  int ionic_adminq_wait(struct ionic_lif *lif, struct ionic_admin_ctx *ctx,
 		if (remaining)
 			break;
 
-		/* interrupt the wait if FW stopped */
+		/* force a check of FW status and break out if FW reset */
+		(void)ionic_heartbeat_check(lif->ionic);
 		if ((test_bit(IONIC_LIF_F_FW_RESET, lif->state) &&
 		     !lif->ionic->idev.fw_status_ready) ||
 		    test_bit(IONIC_LIF_F_FW_STOPPING, lif->state)) {
 			if (do_msg)
-				netdev_err(netdev, "%s (%d) interrupted, FW in reset\n",
-					   name, ctx->cmd.cmd.opcode);
+				netdev_warn(netdev, "%s (%d) interrupted, FW in reset\n",
+					    name, ctx->cmd.cmd.opcode);
 			ctx->comp.comp.status = IONIC_RC_ERROR;
 			return -ENXIO;
 		}
@@ -425,9 +426,9 @@  static int __ionic_dev_cmd_wait(struct ionic *ionic, unsigned long max_seconds,
 	unsigned long start_time;
 	unsigned long max_wait;
 	unsigned long duration;
+	int done = 0;
+	bool fw_up;
 	int opcode;
-	int hb = 0;
-	int done;
 	int err;
 
 	/* Wait for dev cmd to complete, retrying if we get EAGAIN,
@@ -437,31 +438,24 @@  static int __ionic_dev_cmd_wait(struct ionic *ionic, unsigned long max_seconds,
 try_again:
 	opcode = readb(&idev->dev_cmd_regs->cmd.cmd.opcode);
 	start_time = jiffies;
-	do {
+	for (fw_up = ionic_is_fw_running(idev);
+	     !done && fw_up && time_before(jiffies, max_wait);
+	     fw_up = ionic_is_fw_running(idev)) {
 		done = ionic_dev_cmd_done(idev);
 		if (done)
 			break;
 		usleep_range(100, 200);
-
-		/* Don't check the heartbeat on FW_CONTROL commands as they are
-		 * notorious for interrupting the firmware's heartbeat update.
-		 */
-		if (opcode != IONIC_CMD_FW_CONTROL)
-			hb = ionic_heartbeat_check(ionic);
-	} while (!done && !hb && time_before(jiffies, max_wait));
+	}
 	duration = jiffies - start_time;
 
 	dev_dbg(ionic->dev, "DEVCMD %s (%d) done=%d took %ld secs (%ld jiffies)\n",
 		ionic_opcode_to_str(opcode), opcode,
 		done, duration / HZ, duration);
 
-	if (!done && hb) {
-		/* It is possible (but unlikely) that FW was busy and missed a
-		 * heartbeat check but is still alive and will process this
-		 * request, so don't clean the dev_cmd in this case.
-		 */
-		dev_dbg(ionic->dev, "DEVCMD %s (%d) failed - FW halted\n",
-			ionic_opcode_to_str(opcode), opcode);
+	if (!done && !fw_up) {
+		ionic_dev_cmd_clean(ionic);
+		dev_warn(ionic->dev, "DEVCMD %s (%d) interrupted - FW is down\n",
+			 ionic_opcode_to_str(opcode), opcode);
 		return -ENXIO;
 	}