openwrt/target/linux/bcm27xx/patches-5.15/950-0700-net-phy-lan87xx-Decrease-phy-polling-rate.patch
Álvaro Fernández Rojas 20ea6adbf1 bcm27xx: add support for linux v5.15
Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2022-05-17 15:11:22 +02:00

56 lines
1.6 KiB
Diff

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;