netdev - [PATCH net] xirc2ps_cs: fix register access when enabling FullDuplex

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Message-ID: <20250827192645.658496-1-alok.a.tiwari@oracle.com>
Date: Wed, 27 Aug 2025 12:26:43 -0700
From: Alok Tiwari <alok.a.tiwari@...cle.com>
To: andrew+netdev@...n.ch, davem@...emloft.net, edumazet@...gle.com,
        kuba@...nel.org, pabeni@...hat.com, horms@...nel.org,
        netdev@...r.kernel.org
Cc: alok.a.tiwari@...cle.com
Subject: [PATCH net] xirc2ps_cs: fix register access when enabling FullDuplex

The current code incorrectly passes (XIRCREG1_ECR | FullDuplex) as
the register address to GetByte(), instead of fetching the register
value and OR-ing it with FullDuplex. This results in an invalid
register access.

Fix it by reading XIRCREG1_ECR first, then or-ing with FullDuplex
before writing it back.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Alok Tiwari <alok.a.tiwari@...cle.com>
---
This patch is untested due to hardware limitations.
If the Fixes tag is not required, it can be removed.
---
 drivers/net/ethernet/xircom/xirc2ps_cs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/xircom/xirc2ps_cs.c b/drivers/net/ethernet/xircom/xirc2ps_cs.c
index a31d5d5e6593..97e88886253f 100644
--- a/drivers/net/ethernet/xircom/xirc2ps_cs.c
+++ b/drivers/net/ethernet/xircom/xirc2ps_cs.c
@@ -1576,7 +1576,7 @@ do_reset(struct net_device *dev, int full)
 	    msleep(40);			/* wait 40 msec to let it complete */
 	}
 	if (full_duplex)
-	    PutByte(XIRCREG1_ECR, GetByte(XIRCREG1_ECR | FullDuplex));
+	    PutByte(XIRCREG1_ECR, GetByte(XIRCREG1_ECR) | FullDuplex);
     } else {  /* No MII */
 	SelectPage(0);
 	value = GetByte(XIRCREG_ESR);	 /* read the ESR */
-- 
2.50.1