[PATCH 3.19.y-ckt 188/196] net: phy: fix PHY_RUNNING in phy_state_machine

From: Kamal Mostafa
Date: Tue Mar 08 2016 - 19:38:19 EST


3.19.8-ckt16 -stable review patch. If anyone has any objections, please let me know.

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

From: Shaohui Xie <Shaohui.Xie@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
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