[3.19.y-ckt stable] Patch "net: phy: fix PHY_RUNNING in phy_state_machine" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net: phy: fix PHY_RUNNING in phy_state_machine

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt16.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From ef705da105c24754f65929678d26b6d669e92733 Mon Sep 17 00:00:00 2001
From: Shaohui Xie <Shaohui.Xie at freescale.com>
Date: Fri, 14 Aug 2015 12:23:40 +0800
Subject: net: phy: fix PHY_RUNNING in phy_state_machine

commit 11e122cbe90ea5079622fb57bdf2dffe8cf68e57 upstream.

Currently, if phy state is PHY_RUNNING, we always register a CHANGE
when phy works in polling or interrupt ignored, this will make the
adjust_link being called even the phy link did Not changed.

checking the phy link to make sure the link did changed before we
register a CHANGE, if link did not changed, we do nothing.

Signed-off-by: Shaohui Xie <Shaohui.Xie at freescale.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/phy/phy.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 7503c4d..836a956 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -772,6 +772,7 @@ void phy_state_machine(struct work_struct *work)
 			container_of(dwork, struct phy_device, state_queue);
 	bool needs_aneg = false, do_suspend = false, do_resume = false;
 	int err = 0;
+	int old_link;

 	mutex_lock(&phydev->lock);

@@ -855,11 +856,18 @@ void phy_state_machine(struct work_struct *work)
 		phydev->adjust_link(phydev->attached_dev);
 		break;
 	case PHY_RUNNING:
-		/* Only register a CHANGE if we are
-		 * polling or ignoring interrupts
+		/* Only register a CHANGE if we are polling or ignoring
+		 * interrupts and link changed since latest checking.
 		 */
-		if (!phy_interrupt_is_valid(phydev))
-			phydev->state = PHY_CHANGELINK;
+		if (!phy_interrupt_is_valid(phydev)) {
+			old_link = phydev->link;
+			err = phy_read_status(phydev);
+			if (err)
+				break;
+
+			if (old_link != phydev->link)
+				phydev->state = PHY_CHANGELINK;
+		}
 		break;
 	case PHY_CHANGELINK:
 		err = phy_read_status(phydev);
--
2.7.0