[PATCH net-next v2 3/9] net: stmmac: dwmac4: fix PTP message type field extraction

[Russell King (Oracle)]

In dwmac4_wrback_get_rx_status(), the code extracts the PTP message
type from receive descriptor 1 using the dwmac enhanced descriptor
definitions:

	message_type = (rdes1 & ERDES4_MSG_TYPE_MASK) >> 8;

This is defined as:

 #define ERDES4_MSG_TYPE_MASK            GENMASK(11, 8)

The correct definition is RDES1_PTP_MSG_TYPE_MASK, which is also
defined as:

 #define RDES1_PTP_MSG_TYPE_MASK         GENMASK(11, 8)

Use the correct definition, converting to use FIELD_GET() to extract
it without needing an open-coded shift right that is dependent on the
mask definition.

As this change has no effect on the generated code, there is no need
to treat this as a bug fix.

Reviewed-by: Maxime Chevallier <maxime.chevallier at bootlin.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
index aac68dc28dc1..c84b26d51760 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
@@ -108,7 +108,7 @@ static int dwmac4_wrback_get_rx_status(struct stmmac_extra_stats *x,
 		ret = discard_frame;
 	}
 
-	message_type = (rdes1 & ERDES4_MSG_TYPE_MASK) >> 8;
+	message_type = FIELD_GET(RDES1_PTP_MSG_TYPE_MASK, rdes1);
 
 	if (rdes1 & RDES1_IP_HDR_ERROR) {
 		x->ip_hdr_err++;
-- 
2.47.3