[U-Boot] [PATCH] MIIPHYBB: Return 0xFFFF if the PHY is not asserting TA.

[Richard Retanubun]

 From d4c7dd98ac9a3f6fc4949079b84d7d811376cf3d Mon Sep 17 00:00:00 2001
From: Richard Retanubun <RichardRetanubun at RuggedCom.com>
Date: Thu, 2 Jul 2009 13:12:03 -0400
Subject: [PATCH] MIIPHYBB: Return 0xFFFF if the PHY is not asserting TA.

This patch sets the returned value to 0xFFFF if the PHY does not exist
and does not assert Transfer Acknowledge. A NULL check for the value
pointer is also added for buffer overflow protection.

Without this patch 'mii info' will  show 'phantom' devices because the
value will be not be initialized and return with some random value.
---
  drivers/net/phy/miiphybb.c |    7 +++++++
  1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/net/phy/miiphybb.c b/drivers/net/phy/miiphybb.c
index e3c163a..b77c917 100644
--- a/drivers/net/phy/miiphybb.c
+++ b/drivers/net/phy/miiphybb.c
@@ -127,6 +127,11 @@ int bb_miiphy_read (char *devname, unsigned char addr,
  	volatile ioport_t *iop = ioport_addr ((immap_t *) CONFIG_SYS_IMMR, MDIO_PORT);
  #endif

+	if (value == NULL) {
+		puts("NULL value pointer\n");
+		return (-1);
+	}
+
  	miiphy_pre (1, addr, reg);

  	/* tri-state our MDIO I/O pin so we can read */
@@ -145,6 +150,8 @@ int bb_miiphy_read (char *devname, unsigned char addr,
  			MDC (1);
  			MIIDELAY;
  		}
+		/* There is no PHY, set value to 0xFFFF and return */
+		*value = 0xFFFF;
  		return (-1);
  	}

-- 
1.6.2.4