[PATCH v2] net: phy: workaround for buggy cable detection by LAN8700 after cable plugging
From: Igor Plyatov <hidden>
Date: 2015-08-13 19:19:41
Also in:
lkml
Subsystem:
ethernet phy library, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
* Due to HW bug, LAN8700 sometimes does not detect presence of energy in the Ethernet cable in Energy Detect Power-Down mode (e.g while EDPWRDOWN bit is set, the ENERGYON bit does not asserted sometimes). This is a common bug of LAN87xx family of PHY chips. * The lan87xx_read_status() was improved to acquire ENERGYON bit. Its previous algorythm still not reliable on 100 % and sometimes skip cable plugging. Signed-off-by: Igor Plyatov <redacted> --- drivers/net/phy/smsc.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index c0f6479..8559ff1 100644
--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c@@ -104,6 +104,7 @@ static int lan911x_config_init(struct phy_device *phydev) static int lan87xx_read_status(struct phy_device *phydev) { int err = genphy_read_status(phydev); + int i; if (!phydev->link) { /* Disable EDPD to wake up PHY */
@@ -116,8 +117,16 @@ static int lan87xx_read_status(struct phy_device *phydev) if (rc < 0) return rc; - /* Sleep 64 ms to allow ~5 link test pulses to be sent */ - msleep(64); + /* Wait max 640 ms to detect energy */ + for (i = 0; i < 64; i++) { + /* Sleep to allow link test pulses to be sent */ + msleep(10); + rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS); + if (rc < 0) + return rc; + if (rc & MII_LAN83C185_ENERGYON) + break; + }; /* Re-enable EDPD */ rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
@@ -191,7 +200,7 @@ static struct phy_driver smsc_phy_driver[] = { /* basic functions */ .config_aneg = genphy_config_aneg, - .read_status = genphy_read_status, + .read_status = lan87xx_read_status, .config_init = smsc_phy_config_init, .soft_reset = smsc_phy_reset,
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1.7.9.5