From 79206c04a9269f87fd943713db70fbc53ec05ed3 Mon Sep 17 00:00:00 2001 From: Vladimir Zapolskiy Date: Sun, 27 Dec 2015 05:12:24 +0200 Subject: [PATCH] net: lpc32xx: fix ignored MDIO busy wait status on read The change fixes PHY write operation, which incorrectly waits for released busy state before issuing a write operation, this breaks sequential write/read operation logic, because read operation starts immediately on request and it completes, when busy state is gone. Instead of adding the second preceding busy state check to read function, do busy state release check after issuing a write operation, this method of operation is also recommended by the LPC32xx User's Manual, see MII Mgmt Indicators Register notes: For PHY Write if scan is not used: 1. Write 0 to MCMD 2. Write PHY address and register address to MADR 3. Write data to MWTD 4. Wait for busy bit to be cleared in MIND Reported-by: Alexandre Messier Signed-off-by: Vladimir Zapolskiy Tested-by: Alexandre Messier --- drivers/net/lpc32xx_eth.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/lpc32xx_eth.c b/drivers/net/lpc32xx_eth.c index e76e9bc2b5..3ba5b4b1f9 100644 --- a/drivers/net/lpc32xx_eth.c +++ b/drivers/net/lpc32xx_eth.c @@ -304,6 +304,13 @@ static int mii_reg_write(const char *devname, u8 phy_adr, u8 reg_ofs, u16 data) return -EFAULT; } + /* write the phy and reg addressse into the MII address reg */ + writel((phy_adr << MADR_PHY_OFFSET) | (reg_ofs << MADR_REG_OFFSET), + ®s->madr); + + /* write data to the MII write register */ + writel(data, ®s->mwtd); + /* wait till the MII is not busy */ timeout = MII_TIMEOUT; do { @@ -319,13 +326,6 @@ static int mii_reg_write(const char *devname, u8 phy_adr, u8 reg_ofs, u16 data) return -EFAULT; } - /* write the phy and reg addressse into the MII address reg */ - writel((phy_adr << MADR_PHY_OFFSET) | (reg_ofs << MADR_REG_OFFSET), - ®s->madr); - - /* write data to the MII write register */ - writel(data, ®s->mwtd); - /*debug("%s:(adr %d, off %d) <= %04x\n", __func__, phy_adr, reg_ofs, data);*/ -- 2.30.2