From: Brett Creeley <brett.creeley@intel.com>
Date: Thu, 25 Jul 2019 01:55:28 -0700
Subject: ice: Use the software based tail when checking for hung Tx ring
Patch-mainline: v5.4-rc1
Git-commit: c1ddf1f5c4adc1e885dce8533b2245d979f38280
References: jsc#SLE-7926

Currently in ice_get_tx_pending we try to read a Tx ring's tail. This is
then compared with the software based head (next_to_clean) to determine
if we have pending work. This will never work because reading of the Tx
ring's tail is no longer supported. Fix this by using the software based
tail (next_to_use) to determine if there is pending work.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/ice/ice_main.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -41,12 +41,12 @@ static void ice_update_pf_stats(struct i
  * ice_get_tx_pending - returns number of Tx descriptors not processed
  * @ring: the ring of descriptors
  */
-static u32 ice_get_tx_pending(struct ice_ring *ring)
+static u16 ice_get_tx_pending(struct ice_ring *ring)
 {
-	u32 head, tail;
+	u16 head, tail;
 
 	head = ring->next_to_clean;
-	tail = readl(ring->tail);
+	tail = ring->next_to_use;
 
 	if (head != tail)
 		return (head < tail) ?