This patch fix the PHY poller, which can block the whole system. On a
Freescale PPC 834x this result in a delay of 450 us due the slow
communication with the PHY chip.

For PHY chips without interrupts, the status of the ethernet will be
polled every 2 sec. The poll function will read some register of the MII
PHY. The time between the sending the MII_READ_COMMAND and receiving the
result is more the 100 us on a PPC 834x.
   
The patch modifies the poller a lit bit. Only a link status state change
will result in a successive detection of the connection type. The poll
cycle on the other hand will be increased to every seconds.

Together this patch will prevent a blocking of nearly 400 us every two
seconds of the whole system on a PPC 834x.

The patch is against kernel 2.6.33. Please merge it.

Signed-off-by: Stefani Seibold <stef...@seibold.net>
---
 phy.c        |    5 ++---
 phy_device.c |   12 +++++++++---
 2 files changed, 11 insertions(+), 6 deletions(-)

diff -u -N -r -p linux-2.6.33.orig/drivers/net/phy/phy.c 
linux-2.6.33/drivers/net//phy/phy.c
--- linux-2.6.33.orig/drivers/net/phy/phy.c     2010-02-24 19:52:17.000000000 
+0100
+++ linux-2.6.33/drivers/net//phy/phy.c 2010-02-28 22:53:14.725464101 +0100
@@ -871,9 +871,8 @@ void phy_state_machine(struct work_struc
                case PHY_RUNNING:
                        /* Only register a CHANGE if we are
                         * polling */
-                       if (PHY_POLL == phydev->irq)
-                               phydev->state = PHY_CHANGELINK;
-                       break;
+                       if (PHY_POLL != phydev->irq)
+                               break;
                case PHY_CHANGELINK:
                        err = phy_read_status(phydev);
 
diff -u -N -r -p linux-2.6.33.orig/drivers/net/phy/phy_device.c 
linux-2.6.33/drivers/net//phy/phy_device.c
--- linux-2.6.33.orig/drivers/net/phy/phy_device.c      2010-02-24 
19:52:17.000000000 +0100
+++ linux-2.6.33/drivers/net//phy/phy_device.c  2010-02-28 22:53:14.726464145 
+0100
@@ -161,7 +161,7 @@ struct phy_device* phy_device_create(str
        dev->speed = 0;
        dev->duplex = -1;
        dev->pause = dev->asym_pause = 0;
-       dev->link = 1;
+       dev->link = 0;
        dev->interface = PHY_INTERFACE_MODE_GMII;
 
        dev->autoneg = AUTONEG_ENABLE;
@@ -694,10 +694,16 @@ int genphy_update_link(struct phy_device
        if (status < 0)
                return status;
 
-       if ((status & BMSR_LSTATUS) == 0)
+       if ((status & BMSR_LSTATUS) == 0) {
+               if (phydev->link==0)
+                       return 1;
                phydev->link = 0;
-       else
+       }
+       else {
+               if (phydev->link==1)
+                       return 1;
                phydev->link = 1;
+       }
 
        return 0;
 }


_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Reply via email to