[PATCH net-next 6/6] r8152: add byte_enable for ocp_read_word function

[Hayes Wang <hayeswang@realtek.com>]

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:b4d99def.
The origin method always reads 4 bytes data, and it may have problem
when reading the PHY regiters.

The new method is supported since RTL8152B, 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>
---
 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 2fd4944..0bb7c1b 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -945,11 +945,13 @@ 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);
-- 
2.4.11