netdev - [PATCH] phy: fix phy_id detection also for broken hardware.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1227196656-4361-1-git-send-email-peppe.cavallaro@st.com>
Date:	Thu, 20 Nov 2008 16:57:36 +0100
From:	Giuseppe CAVALLARO <peppe.cavallaro@...com>
To:	netdev@...r.kernel.org
Cc:	davem@...emloft.net, giulio.benetti@...ronovasrl.com,
	Giuseppe Cavallaro <peppe.cavallaro@...com>
Subject: [PATCH] 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: Giuseppe Cavallaro <peppe.cavallaro@...com>
---
 drivers/net/phy/phy_device.c |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8fb1fac..effa489 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -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);
-- 
1.5.6.5

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html