All of lore.kernel.org
 help / color / mirror / Atom feed
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: Joakim Zhang <qiangqing.zhang@nxp.com>
Cc: Andrew Lunn <andrew@lunn.ch>, Vladimir Oltean <olteanv@gmail.com>,
	"peppe.cavallaro@st.com" <peppe.cavallaro@st.com>,
	"alexandre.torgue@foss.st.com" <alexandre.torgue@foss.st.com>,
	"joabreu@synopsys.com" <joabreu@synopsys.com>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"kuba@kernel.org" <kuba@kernel.org>,
	"mcoquelin.stm32@gmail.com" <mcoquelin.stm32@gmail.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"f.fainelli@gmail.com" <f.fainelli@gmail.com>,
	"hkallweit1@gmail.com" <hkallweit1@gmail.com>,
	dl-linux-imx <linux-imx@nxp.com>
Subject: Re: [PATCH] net: stmmac: fix MAC not working when system resume back with WoL enabled
Date: Fri, 3 Sep 2021 21:12:10 +0100	[thread overview]
Message-ID: <20210903201210.GF1350@shell.armlinux.org.uk> (raw)
In-Reply-To: <20210903120127.GW22278@shell.armlinux.org.uk>

Hi,

Here's a patch to try - you'll need to integrate the new calls into
stmmac's suspend and resume hooks. Obviously, given my previous
comments, this isn't tested!

I didn't need to repeat the mac_wol boolean to phylink_resume as we
can record the state internally - mac_wol should not change between
a call to phylink_suspend() and subsequent phylink_resume() anyway.

mac_wol should only be true if the MAC is involved in processing
packets for WoL, false otherwise.

Please let me know if this resolves your stmmac WoL issue.

Thanks.

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index f0c769027145..c4d0de04416a 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -33,6 +33,7 @@
 enum {
 	PHYLINK_DISABLE_STOPPED,
 	PHYLINK_DISABLE_LINK,
+	PHYLINK_DISABLE_MAC_WOL,
 };
 
 /**
@@ -1313,6 +1314,9 @@ EXPORT_SYMBOL_GPL(phylink_start);
  * network device driver's &struct net_device_ops ndo_stop() method.  The
  * network device's carrier state should not be changed prior to calling this
  * function.
+ *
+ * This will synchronously bring down the link if the link is not already
+ * down (in other words, it will trigger a mac_link_down() method call.)
  */
 void phylink_stop(struct phylink *pl)
 {
@@ -1338,6 +1342,81 @@ void phylink_stop(struct phylink *pl)
 }
 EXPORT_SYMBOL_GPL(phylink_stop);
 
+
+/**
+ * phylink_suspend() - handle a network device suspend event
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ * @mac_wol: true if the MAC needs to receive packets for Wake-on-Lan
+ *
+ * Handle a network device suspend event. There are several cases:
+ * - If Wake-on-Lan is not active, we can bring down the link between
+ *   the MAC and PHY by calling phylink_stop().
+ * - If Wake-on-Lan is active, and being handled only by the PHY, we
+ *   can also bring down the link between the MAC and PHY.
+ * - If Wake-on-Lan is active, but being handled by the MAC, the MAC
+ *   still needs to receive packets, so we can not bring the link down.
+ */
+void phylink_suspend(struct phylink *pl, bool mac_wol)
+{
+	ASSERT_RTNL();
+
+	if (mac_wol && (!pl->netdev || pl->netdev->wol_enabled)) {
+		/* Wake-on-Lan enabled, MAC handling */
+		mutex_lock(&pl->state_mutex);
+
+		/* Stop the resolver bringing the link up */
+		__set_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state);
+
+		/* Disable the carrier, to prevent transmit timeouts,
+		 * but one would hope all packets have been sent.
+		 */
+		netif_carrier_off(pl->netdev);
+
+		/* We do not call mac_link_down() here as we want the
+		 * link to remain up to receive the WoL packets.
+		 */
+		mutex_unlock(&pl->state_mutex);
+	} else {
+		phylink_stop(pl);
+	}
+}
+EXPORT_SYMBOL_GPL(phylink_suspend);
+
+/**
+ * phylink_resume() - handle a network device resume event
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ *
+ * Undo the effects of phylink_suspend(), returning the link to an
+ * operational state.
+ */
+void phylink_resume(struct phylink *pl)
+{
+	ASSERT_RTNL();
+
+	if (test_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state)) {
+		/* Wake-on-Lan enabled, MAC handling */
+
+		/* Call mac_link_down() so we keep the overall state balanced.
+		 * Do this under the state_mutex lock for consistency. This
+		 * will cause a "Link Down" message to be printed during
+		 * resume, which is harmless - the true link state will be
+		 * printed when we run a resolve.
+		 */
+		mutex_lock(&pl->state_mutex);
+		phylink_link_down(pl);
+		mutex_unlock(&pl->state_mutex);
+
+		/* Re-apply the link parameters so that all the settings get
+		 * restored to the MAC.
+		 */
+		phylink_mac_initial_config(pl, true);
+		phylink_enable_and_run_resolve(pl, PHYLINK_DISABLE_MAC_WOL);
+	} else {
+		phylink_start(pl);
+	}
+}
+EXPORT_SYMBOL_GPL(phylink_resume);
+
 /**
  * phylink_ethtool_get_wol() - get the wake on lan parameters for the PHY
  * @pl: a pointer to a &struct phylink returned from phylink_create()
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index bdeec800da5c..ba0ab7126b96 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -462,6 +462,9 @@ void phylink_mac_change(struct phylink *, bool up);
 void phylink_start(struct phylink *);
 void phylink_stop(struct phylink *);
 
+void phylink_suspend(struct phylink *pl, bool mac_wol);
+void phylink_resume(struct phylink *pl);
+
 void phylink_ethtool_get_wol(struct phylink *, struct ethtool_wolinfo *);
 int phylink_ethtool_set_wol(struct phylink *, struct ethtool_wolinfo *);
 

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

  reply	other threads:[~2021-09-03 20:12 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-01  9:02 Joakim Zhang
2021-09-01  9:13 ` Russell King (Oracle)
2021-09-01 10:21   ` Joakim Zhang
2021-09-01 12:56     ` Russell King (Oracle)
2021-09-02  7:01       ` Joakim Zhang
2021-09-01 15:40     ` Heiner Kallweit
2021-09-02  7:35       ` Joakim Zhang
2021-09-01  9:21 ` Vladimir Oltean
2021-09-01 10:25   ` Joakim Zhang
2021-09-01 10:56     ` Vladimir Oltean
2021-09-01 11:42       ` Joakim Zhang
2021-09-01 13:25         ` Russell King (Oracle)
2021-09-02  7:28           ` Joakim Zhang
2021-09-02  8:32             ` Russell King (Oracle)
2021-09-02 10:26               ` Joakim Zhang
2021-09-02 10:49                 ` Russell King (Oracle)
2021-09-02 11:15                   ` Joakim Zhang
2021-09-02 12:24                     ` Andrew Lunn
2021-09-03  6:51                       ` Joakim Zhang
2021-09-03  8:01                         ` Russell King (Oracle)
2021-09-03  8:39                           ` Joakim Zhang
2021-09-03  9:32                             ` Russell King (Oracle)
2021-09-03 11:04                               ` Joakim Zhang
2021-09-03 12:01                                 ` Russell King (Oracle)
2021-09-03 20:12                                   ` Russell King - ARM Linux admin [this message]
2021-09-06  2:29                                     ` Joakim Zhang
2021-09-06  9:34                                       ` Russell King (Oracle)
2021-09-06 10:41                                         ` Joakim Zhang
2021-09-06 11:21                                           ` Russell King (Oracle)
2021-09-06 13:23                                             ` Andrew Lunn
2021-09-07  8:52                                             ` Russell King (Oracle)
2021-09-06  2:21                                   ` Joakim Zhang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210903201210.GF1350@shell.armlinux.org.uk \
    --to=linux@armlinux.org.uk \
    --cc=alexandre.torgue@foss.st.com \
    --cc=andrew@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=f.fainelli@gmail.com \
    --cc=hkallweit1@gmail.com \
    --cc=joabreu@synopsys.com \
    --cc=kuba@kernel.org \
    --cc=linux-imx@nxp.com \
    --cc=mcoquelin.stm32@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=olteanv@gmail.com \
    --cc=peppe.cavallaro@st.com \
    --cc=qiangqing.zhang@nxp.com \
    --subject='Re: [PATCH] net: stmmac: fix MAC not working when system resume back with WoL enabled' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.