[PATCH net 1/1] ionic: fix fw_status read

[PATCH net 1/1] ionic: fix fw_status read

[Shannon Nelson]

The fw_status field is only 8 bits, so fix the read.  Also,
we only want to look at the one status bit, to allow for future
use of the other bits, and watch for a bad PCI read.

Fixes: 97ca486592c0 ("ionic: add heartbeat check")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
---
 drivers/net/ethernet/pensando/ionic/ionic_dev.c | 11 +++++++----
 drivers/net/ethernet/pensando/ionic/ionic_if.h  |  1 +
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.c b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
index 87f82f36812f..46107de5e6c3 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
@@ -103,7 +103,7 @@ int ionic_heartbeat_check(struct ionic *ionic)
 {
 	struct ionic_dev *idev = &ionic->idev;
 	unsigned long hb_time;
-	u32 fw_status;
+	u8 fw_status;
 	u32 hb;
 
 	/* wait a little more than one second before testing again */
@@ -111,9 +111,12 @@ int ionic_heartbeat_check(struct ionic *ionic)
 	if (time_before(hb_time, (idev->last_hb_time + ionic->watchdog_period)))
 		return 0;
 
-	/* firmware is useful only if fw_status is non-zero */
-	fw_status = ioread32(&idev->dev_info_regs->fw_status);
-	if (!fw_status)
+	/* firmware is useful only if the running bit is set and
+	 * fw_status != 0xff (bad PCI read)
+	 */
+	fw_status = ioread8(&idev->dev_info_regs->fw_status);
+	if (fw_status == 0xff ||
+	    !(fw_status & IONIC_FW_STS_F_RUNNING))
 		return -ENXIO;
 
 	/* early FW has no heartbeat, else FW will return non-zero */
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_if.h b/drivers/net/ethernet/pensando/ionic/ionic_if.h
index ce07c2931a72..54547d53b0f2 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_if.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_if.h
@@ -2445,6 +2445,7 @@ union ionic_dev_info_regs {
 		u8     version;
 		u8     asic_type;
 		u8     asic_rev;
+#define IONIC_FW_STS_F_RUNNING	0x1
 		u8     fw_status;
 		u32    fw_heartbeat;
 		char   fw_version[IONIC_DEVINFO_FWVERS_BUFLEN];
-- 
2.17.1

Re: [PATCH net 1/1] ionic: fix fw_status read

[David Miller]

From: Shannon Nelson <snelson@pensando.io>
Date: Wed, 19 Feb 2020 14:59:42 -0800

> The fw_status field is only 8 bits, so fix the read.  Also,
> we only want to look at the one status bit, to allow for future
> use of the other bits, and watch for a bad PCI read.
> 
> Fixes: 97ca486592c0 ("ionic: add heartbeat check")
> Signed-off-by: Shannon Nelson <snelson@pensando.io>

Applied and queued up for -stable, thanks.