crans/openwrt-chaoscalmer-uappro
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

ar8216: decrease page switch wait time

Browse source 
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 <hkallweit1@gmail.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44103 3c298f89-4303-0410-b956-a3cf2f4a3e73
This commit is contained in:
nbd 2015-01-24 19:42:01 +00:00
parent f806566385
commit a8740ff7fc
2 changed files with 9 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

6
target/linux/generic/files/drivers/net/phy/ar8216.c
View file

@ -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;

6
target/linux/generic/files/drivers/net/phy/ar8216.h
View file

@ -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