From: Michael Brown <mcb30@ipxe.org>
Date: Thu, 23 Aug 2012 11:38:37 +0000 (+0100)
Subject: [realtek] Use read-modify-write to check for C+ Command register
X-Git-Tag: v1.20.1~1666
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0e61beb26f789da01a566ff4bfdf571faacb9ce3;p=thirdparty%2Fipxe.git

[realtek] Use read-modify-write to check for C+ Command register

Some bits in the C+ Command register are always one.  Testing for the
presence of the register must allow for this.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/drivers/net/realtek.c b/src/drivers/net/realtek.c
index 77df64e61..f63f25f27 100644
--- a/src/drivers/net/realtek.c
+++ b/src/drivers/net/realtek.c
@@ -879,8 +879,9 @@ static void realtek_detect ( struct realtek_nic *rtl ) {
 	 * Try to enable C+ mode and PCI Dual Address Cycle (for
 	 * 64-bit systems), if supported.
 	 */
-	cpcr = ( RTL_CPCR_DAC | RTL_CPCR_MULRW | RTL_CPCR_CPRX |
-		 RTL_CPCR_CPTX );
+	cpcr = readw ( rtl->regs + RTL_CPCR );
+	cpcr |= ( RTL_CPCR_DAC | RTL_CPCR_MULRW | RTL_CPCR_CPRX |
+		  RTL_CPCR_CPTX );
 	writew ( cpcr, rtl->regs + RTL_CPCR );
 	check_cpcr = readw ( rtl->regs + RTL_CPCR );
 
@@ -890,7 +891,7 @@ static void realtek_detect ( struct realtek_nic *rtl ) {
 		rtl->have_phy_regs = 1;
 		rtl->tppoll = RTL_TPPOLL_8169;
 	} else {
-		if ( check_cpcr == cpcr ) {
+		if ( ( check_cpcr == cpcr ) && ( cpcr != 0xffff ) ) {
 			DBGC ( rtl, "REALTEK %p appears to be an RTL8139C+\n",
 			       rtl );
 			rtl->tppoll = RTL_TPPOLL_8139CP;