diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.15/950-0700-net-phy-lan87xx-Decrease-phy-polling-rate.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.15/950-0700-net-phy-lan87xx-Decrease-phy-polling-rate.patch | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.15/950-0700-net-phy-lan87xx-Decrease-phy-polling-rate.patch b/target/linux/bcm27xx/patches-5.15/950-0700-net-phy-lan87xx-Decrease-phy-polling-rate.patch new file mode 100644 index 0000000000..6693f86aea --- /dev/null +++ b/target/linux/bcm27xx/patches-5.15/950-0700-net-phy-lan87xx-Decrease-phy-polling-rate.patch @@ -0,0 +1,55 @@ +From 01649f43afb30df3c7450fd09c04a5a8ee6cb2c1 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.com> +Date: Thu, 3 Feb 2022 15:51:41 +0000 +Subject: [PATCH] net: phy: lan87xx: Decrease phy polling rate + +Polling at 100Hz for 1.5s consumes quite a bit of kworker time with no +obvious benefit. Reduce that polling rate to ~6Hz. + +To further save CPU and power, defer the next poll if no energy is +detected. + +See: https://github.com/raspberrypi/linux/issues/4780 + +Signed-off-by: Phil Elwell <phil@raspberrypi.com> +--- + drivers/net/phy/smsc.c | 10 +++++++++- + 1 file changed, 9 insertions(+), 1 deletion(-) + +--- a/drivers/net/phy/smsc.c ++++ b/drivers/net/phy/smsc.c +@@ -218,6 +218,8 @@ static int lan87xx_read_status(struct ph + int err = genphy_read_status(phydev); + + if (!phydev->link && priv->energy_enable) { ++ int energy_detected; ++ + /* Disable EDPD to wake up PHY */ + int rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS); + if (rc < 0) +@@ -233,7 +235,7 @@ static int lan87xx_read_status(struct ph + */ + read_poll_timeout(phy_read, rc, + rc & MII_LAN83C185_ENERGYON || rc < 0, +- 10000, 1500000, true, phydev, ++ 150000, 1500000, true, phydev, + MII_LAN83C185_CTRL_STATUS); + if (rc < 0) + return rc; +@@ -243,10 +245,16 @@ static int lan87xx_read_status(struct ph + if (rc < 0) + return rc; + ++ energy_detected = !!(rc & MII_LAN83C185_ENERGYON); ++ + rc = phy_write(phydev, MII_LAN83C185_CTRL_STATUS, + rc | MII_LAN83C185_EDPWRDOWN); + if (rc < 0) + return rc; ++ ++ /* Save CPU and power by deferring the next poll */ ++ if (!energy_detected) ++ msleep(2000); + } + + return err; |