Commit 6436cbcd authored by Giuseppe Cavallaro's avatar Giuseppe Cavallaro Committed by David S. Miller
Browse files

phy: fix phy_id detection also for broken hardware. 



This patch fixes the case when the phy_ids is mostly Fs and in some case 0x0
due to broken hardware.

Signed-off-by: default avatarGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 75e07fc3

drivers/net/phy/phy_device.c

+11 −2
Original line number Diff line number Diff line
@@ -227,8 +227,17 @@ struct phy_device * get_phy_device(struct mii_bus *bus, int addr) 
	if (r)

		return ERR_PTR(r);



	/* If the phy_id is all Fs or all 0s, there is no device there */

	if ((0xffff == phy_id) || (0x00 == phy_id))

	/* If the phy_id is mostly Fs, there is no device there */

	if ((phy_id & 0x1fffffff) == 0x1fffffff)

		return NULL;



	/*

	 * Broken hardware is sometimes missing the pull down resistor on the

	 * MDIO line, which results in reads to non-existent devices returning

	 * 0 rather than 0xffff. Catch this here and treat 0 as a non-existent

	 * device as well.

	 */

	if (phy_id == 0)

		return NULL;



	dev = phy_device_create(bus, addr, phy_id);