Commit 0cc8bddb authored by Peter Geis's avatar Peter Geis Committed by Jakub Kicinski
Browse files

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: 48e8c6f1 ("net: phy: add driver for Motorcomm yt8511 phy")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarPeter Geis <pgwipeout@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 546d6bad

drivers/net/phy/motorcomm.c

+8 −7
Original line number Diff line number Diff line
@@ -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)