From 024a07bacf8287a6ddfa83e9d5b951c5e8b4070e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timo=20Ter=C3=A4s?= Date: Sun, 6 Jun 2010 15:38:47 -0700 Subject: r8169: fix random mdio_write failures MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some configurations need delay between the "write completed" indication and new write to work reliably. Realtek driver seems to use longer delay when polling the "write complete" bit, so it waits long enough between writes with high probability (but could probably break too). This patch adds a new udelay to make sure we wait unconditionally some time after the write complete indication. This caused a regression with XID 18000000 boards when the board specific phy configuration writing many mdio registers was added in commit 2e955856ff (r8169: phy init for the 8169scd). Some of the configration mdio writes would almost always fail, and depending on failure might leave the PHY in non-working state. Signed-off-by: Timo Teräs Acked-off-by: Francois Romieu Signed-off-by: David S. Miller --- drivers/net/r8169.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/net/r8169.c') diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c index 217e709bda3e..03a8318d90a2 100644 --- a/drivers/net/r8169.c +++ b/drivers/net/r8169.c @@ -559,6 +559,11 @@ static void mdio_write(void __iomem *ioaddr, int reg_addr, int value) break; udelay(25); } + /* + * Some configurations require a small delay even after the write + * completed indication or the next write might fail. + */ + udelay(25); } static int mdio_read(void __iomem *ioaddr, int reg_addr) -- cgit v1.2.2 From 81a95f049962ec20a9aed888e676208b206f0f2e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timo=20Ter=C3=A4s?= Date: Wed, 9 Jun 2010 17:31:48 -0700 Subject: r8169: fix mdio_read and update mdio_write according to hw specs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Francois Romieu Signed-off-by: David S. Miller --- drivers/net/r8169.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'drivers/net/r8169.c') diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c index 03a8318d90a2..96b6cfbf0a3a 100644 --- a/drivers/net/r8169.c +++ b/drivers/net/r8169.c @@ -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; } -- cgit v1.2.2