From 0cc8bddb5b0665283baba6d89684630663c0ccbd Mon Sep 17 00:00:00 2001 From: Peter Geis Date: Sat, 29 May 2021 07:05:56 -0400 Subject: [PATCH] net: phy: abort loading yt8511 driver in unsupported modes While investigating the clang `ge` uninitialized variable report, it was discovered the default switch would have unintended consequences. Due to the switch to __phy_modify, the driver would modify the ID values in the default scenario. Fix this by promoting the interface mode switch and aborting when the mode is not a supported RGMII mode. This prevents the `ge` and `fe` variables from ever being used uninitialized. Fixes: 48e8c6f1612b ("net: phy: add driver for Motorcomm yt8511 phy") Reported-by: kernel test robot Reviewed-by: Andrew Lunn Signed-off-by: Peter Geis Signed-off-by: Jakub Kicinski --- drivers/net/phy/motorcomm.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/net/phy/motorcomm.c b/drivers/net/phy/motorcomm.c index 68cd19540c67..7e6ac2c5e27e 100644 --- a/drivers/net/phy/motorcomm.c +++ b/drivers/net/phy/motorcomm.c @@ -53,15 +53,10 @@ static int yt8511_config_init(struct phy_device *phydev) int oldpage, ret = 0; unsigned int ge, fe; - /* set clock mode to 125mhz */ oldpage = phy_select_page(phydev, YT8511_EXT_CLK_GATE); if (oldpage < 0) goto err_restore_page; - ret = __phy_modify(phydev, YT8511_PAGE, 0, YT8511_CLK_125M); - if (ret < 0) - goto err_restore_page; - /* set rgmii delay mode */ switch (phydev->interface) { case PHY_INTERFACE_MODE_RGMII: @@ -80,14 +75,20 @@ static int yt8511_config_init(struct phy_device *phydev) ge = YT8511_DELAY_RX | YT8511_DELAY_GE_TX_EN; fe = YT8511_DELAY_FE_TX_EN; break; - default: /* leave everything alone in other modes */ - break; + default: /* do not support other modes */ + ret = -EOPNOTSUPP; + goto err_restore_page; } ret = __phy_modify(phydev, YT8511_PAGE, (YT8511_DELAY_RX | YT8511_DELAY_GE_TX_EN), ge); if (ret < 0) goto err_restore_page; + /* set clock mode to 125mhz */ + ret = __phy_modify(phydev, YT8511_PAGE, 0, YT8511_CLK_125M); + if (ret < 0) + goto err_restore_page; + /* fast ethernet delay is in a separate page */ ret = __phy_write(phydev, YT8511_PAGE_SELECT, YT8511_EXT_DELAY_DRIVE); if (ret < 0) -- 2.25.1