From d8fbd27469fc02049c674de296a3263bef089131 Mon Sep 17 00:00:00 2001
From: hayeswang <hayeswang@realtek.com>
Date: Thu, 15 Jun 2017 14:44:04 +0800
Subject: [PATCH] r8152: add byte_enable for ocp_read_word function
Git-commit: d8fbd27469fc02049c674de296a3263bef089131
Patch-mainline: v4.13-rc1
References: bsc#1119749

Add byte_enable for ocp_read_word() to replace reading 4
bytes data with reading the desired 2 bytes data.

This is used to avoid the issue which is described in
commit b4d99def0938 ("r8152: remove sram_read"). The
original method always reads 4 bytes data, and it may
have problem when reading the PHY registers.

The new method is supported since RTL8153B, but it
doesn't influence the previous chips. The bits of the
byte_enable for the previous chips are the reserved
bits, and the hw would ignore them.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/usb/r8152.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 932060c3bdc2..3a29072dc622 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -962,11 +962,13 @@ static u16 ocp_read_word(struct r8152 *tp, u16 type, u16 index)
 {
 	u32 data;
 	__le32 tmp;
+	u16 byen = BYTE_EN_WORD;
 	u8 shift = index & 2;
 
 	index &= ~3;
+	byen <<= shift;
 
-	generic_ocp_read(tp, index, sizeof(tmp), &tmp, type);
+	generic_ocp_read(tp, index, sizeof(tmp), &tmp, type | byen);
 
 	data = __le32_to_cpu(tmp);
 	data >>= (shift * 8);
-- 
2.19.2