[PATCH] net: stmmac: selftests: Prevent RXC from being disabled in LPI

[Maxime Chevallier]

RXC is critical to the RX path and some register banks in stmmac, so
it is blocked from being disabled in LPI when we know we're going
to need that clock.

During selftests, we're in MAC loopback so the PHY may enter LPI and
stop its RXC. This will prevent the RX path from properly receiving
the looped-back packets, hence failing the selftests.

As the NETIF_F_VLAN_FEATURES may be empty on some platforms once the
software vlan stripping is removed, the phylink config attribute
'eee_rx_clk_stop_enable' may no longer be inconditionnally set to
true, hence allowing RXC to be disabled during LPI on platforms
that don't have any VLAN features.

Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
index cd7dc99095a0..982c711a9700 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
@@ -2044,12 +2044,14 @@ void stmmac_selftest_run(struct net_device *dev,
 		return;
 	}
 
+	phylink_rx_clk_stop_block(priv->phylink);
 	for (i = 0; i < count; i++) {
 		ret = stmmac_selftests[i].fn(priv);
 		if (ret && (ret != -EOPNOTSUPP))
 			etest->flags |= ETH_TEST_FL_FAILED;
 		buf[i] = ret;
 	}
+	phylink_rx_clk_stop_unblock(priv->phylink);
 
 	stmmac_set_mac_loopback(priv, priv->ioaddr, false);
 }
-- 
2.55.0