[PATCH net-next v5 1/8] net: phylink: Document MAC_(A)SYM_PAUSE

[Sean Anderson]

This documents the possible MLO_PAUSE_* settings which can result from
different combinations of MLO_(A)SYM_PAUSE. These are more-or-less a
direct consequence of IEEE 802.3 Table 28B-2.

Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxx>
---

(no changes since v3)

Changes in v3:
- New

 include/linux/phylink.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 6d06896fc20d..a431a0b0d217 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -21,6 +21,22 @@ enum {
 	MLO_AN_FIXED,	/* Fixed-link mode */
 	MLO_AN_INBAND,	/* In-band protocol */
 
+	/* MAC_SYM_PAUSE and MAC_ASYM_PAUSE correspond to the PAUSE and
+	 * ASM_DIR bits used in autonegotiation, respectively. See IEEE 802.3
+	 * Annex 28B for more information.
+	 *
+	 * The following table lists the values of MLO_PAUSE_* (aside from
+	 * MLO_PAUSE_AN) which might be requested depending on the results of
+	 * autonegotiation or user configuration:
+	 *
+	 * MAC_SYM_PAUSE MAC_ASYM_PAUSE Valid pause modes
+	 * ============= ============== ==============================
+	 *             0              0 MLO_PAUSE_NONE
+	 *             0              1 MLO_PAUSE_NONE, MLO_PAUSE_TX
+	 *             1              0 MLO_PAUSE_NONE, MLO_PAUSE_TXRX
+	 *             1              1 MLO_PAUSE_NONE, MLO_PAUSE_TXRX,
+	 *                              MLO_PAUSE_RX
+	 */
 	MAC_SYM_PAUSE	= BIT(0),
 	MAC_ASYM_PAUSE	= BIT(1),
 	MAC_10HD	= BIT(2),
-- 
2.35.1.1320.gc452695387.dirty