net: ethernet: ti: cpsw: fix sw timestamping for non PTP packets

The cpts can timestmap only ptp packets at this moment, so driver
cannot mark every packet as though it's going to be timestamped,
only because h/w timestamping for given skb is enabled with
SKBTX_HW_TSTAMP. It doesn't allow to use sw timestamping, as result
outgoing packet is not timestamped at all if it's not PTP and h/w
timestamping is enabled. So, fix it by setting SKBTX_IN_PROGRESS
only for PTP packets.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw.c

@@ -1598,6 +1598,7 @@ static netdev_tx_t cpsw_ndo_start_xmit(struct sk_buff *skb,
 {
 	struct cpsw_priv *priv = netdev_priv(ndev);
 	struct cpsw_common *cpsw = priv->cpsw;
+	struct cpts *cpts = cpsw->cpts;
 	struct netdev_queue *txq;
 	struct cpdma_chan *txch;
 	int ret, q_idx;
@@ -1609,7 +1610,7 @@ static netdev_tx_t cpsw_ndo_start_xmit(struct sk_buff *skb,
 	}
 
 	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
-	    cpts_is_tx_enabled(cpsw->cpts))
+	    cpts_is_tx_enabled(cpts) && cpts_can_timestamp(cpts, skb))
 		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 
 	q_idx = skb_get_queue_mapping(skb);

drivers/net/ethernet/ti/cpts.h

@@ -30,6 +30,7 @@
 #include <linux/of.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/skbuff.h>
+#include <linux/ptp_classify.h>
 #include <linux/timecounter.h>
 
 struct cpsw_cpts {
@@ -155,6 +156,16 @@ static inline bool cpts_is_tx_enabled(struct cpts *cpts)
 	return !!cpts->tx_enable;
 }
 
+static inline bool cpts_can_timestamp(struct cpts *cpts, struct sk_buff *skb)
+{
+	unsigned int class = ptp_classify_raw(skb);
+
+	if (class == PTP_CLASS_NONE)
+		return false;
+
+	return true;
+}
+
 #else
 struct cpts;
 
@@ -203,6 +214,11 @@ static inline bool cpts_is_tx_enabled(struct cpts *cpts)
 {
 	return false;
 }
+
+static inline bool cpts_can_timestamp(struct cpts *cpts, struct sk_buff *skb)
+{
+	return false;
+}
 #endif