From dda70e257cb90da42f51be7de96e5a04c7ce918f Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 24 Jan 2015 19:42:01 +0000 Subject: [PATCH] ar8216: decrease page switch wait time Until a few years ago the page switch wait time was set to msleep(1) what was changed to usleep_range(1000, 2000) later. I can not imagine that a low-level operation like switching page on register level takes so much time. Most likely the value of 1ms was initially set to check whether it fixes an issue and then remained w/o further checking whether also a smaller value would be sufficient. Now the wait time is set to 5us and I successfully tested this on AR8327. IMHO 5us should be plenty of time for all supported chips. However I couldn't test this due to missing hardware. If other chips should need a longer wait time we can add the wait time as a parameter to the ar8xxx_chip struct. Signed-off-by: Heiner Kallweit SVN-Revision: 44103 --- target/linux/generic/files/drivers/net/phy/ar8216.c | 6 +++--- target/linux/generic/files/drivers/net/phy/ar8216.h | 6 ++++++ 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/target/linux/generic/files/drivers/net/phy/ar8216.c b/target/linux/generic/files/drivers/net/phy/ar8216.c index 130ebf7126..8a40a322b5 100644 --- a/target/linux/generic/files/drivers/net/phy/ar8216.c +++ b/target/linux/generic/files/drivers/net/phy/ar8216.c @@ -260,7 +260,7 @@ ar8xxx_read(struct ar8xxx_priv *priv, int reg) mutex_lock(&bus->mdio_lock); bus->write(bus, 0x18, 0, page); - usleep_range(1000, 2000); /* wait for the page switch to propagate */ + wait_for_page_switch(); val = mii_read32(priv, 0x10 | r2, r1); mutex_unlock(&bus->mdio_lock); @@ -279,7 +279,7 @@ ar8xxx_write(struct ar8xxx_priv *priv, int reg, u32 val) mutex_lock(&bus->mdio_lock); bus->write(bus, 0x18, 0, page); - usleep_range(1000, 2000); /* wait for the page switch to propagate */ + wait_for_page_switch(); mii_write32(priv, 0x10 | r2, r1, val); mutex_unlock(&bus->mdio_lock); @@ -297,7 +297,7 @@ ar8xxx_rmw(struct ar8xxx_priv *priv, int reg, u32 mask, u32 val) mutex_lock(&bus->mdio_lock); bus->write(bus, 0x18, 0, page); - usleep_range(1000, 2000); /* wait for the page switch to propagate */ + wait_for_page_switch(); ret = mii_read32(priv, 0x10 | r2, r1); ret &= ~mask; diff --git a/target/linux/generic/files/drivers/net/phy/ar8216.h b/target/linux/generic/files/drivers/net/phy/ar8216.h index 2d025ae835..77df506256 100644 --- a/target/linux/generic/files/drivers/net/phy/ar8216.h +++ b/target/linux/generic/files/drivers/net/phy/ar8216.h @@ -555,4 +555,10 @@ ar8xxx_reg_clear(struct ar8xxx_priv *priv, int reg, u32 val) ar8xxx_rmw(priv, reg, val, 0); } +static inline void +wait_for_page_switch(void) +{ + udelay(5); +} + #endif -- 2.30.2