r8169: fix mdio_read and update mdio_write according to hw specs

Realtek confirmed that a 20us delay is needed after mdio_read and
mdio_write operations. Reduce the delay in mdio_write, and add it
to mdio_read too. Also add a comment that the 20us is from hw specs.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Timo Teräs 2010-06-09 17:31:48 -07:00 committed by David S. Miller
parent ebedb22d2b
commit 81a95f0499

View File

@ -560,10 +560,10 @@ static void mdio_write(void __iomem *ioaddr, int reg_addr, int value)
udelay(25);
}
/*
* Some configurations require a small delay even after the write
* completed indication or the next write might fail.
* According to hardware specs a 20us delay is required after write
* complete indication, but before sending next command.
*/
udelay(25);
udelay(20);
}
static int mdio_read(void __iomem *ioaddr, int reg_addr)
@ -583,6 +583,12 @@ static int mdio_read(void __iomem *ioaddr, int reg_addr)
}
udelay(25);
}
/*
* According to hardware specs a 20us delay is required after read
* complete indication, but before sending next command.
*/
udelay(20);
return value;
}