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[RFC,net-next,2/3] net: phylink: add functions to block/unblock rx clock stop

Message ID E1tpPtu-005Soa-Ac@rmk-PC.armlinux.org.uk (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series net: stmmac: approach 2 to solve EEE LPI reset issues | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 0 this patch: 12
netdev/build_tools success Errors and warnings before: 26 (+0) this patch: 26 (+0)
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang fail Errors and warnings before: 0 this patch: 13
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 75 this patch: 86
netdev/checkpatch warning CHECK: Please don't use multiple blank lines WARNING: function definition argument 'struct phylink *' should also have an identifier name WARNING: suspect code indent for conditional statements (8, 12)
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 29 this patch: 29
netdev/source_inline success Was 0 now: 0

Commit Message

Russell King (Oracle) March 4, 2025, 10:53 a.m. UTC
Some MACs require the PHY receive clock to be running to complete setup
actions. This may fail if the PHY has negotiated EEE, the MAC supports
receive clock stop, and the link has entered LPI state. Provide a pair
of APIs that MAC drivers can use to temporarily block the PHY disabling
the receive clock.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phylink.c | 62 +++++++++++++++++++++++++++++++--------
 include/linux/phylink.h   |  3 ++
 2 files changed, 53 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 0aae0bb2a254..9a62808cf935 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -88,6 +88,7 @@  struct phylink {
 	bool mac_enable_tx_lpi;
 	bool mac_tx_clk_stop;
 	u32 mac_tx_lpi_timer;
+	u8 mac_rx_clk_stop_blocked;
 
 	struct sfp_bus *sfp_bus;
 	bool sfp_may_have_phy;
@@ -2592,6 +2593,55 @@  void phylink_stop(struct phylink *pl)
 }
 EXPORT_SYMBOL_GPL(phylink_stop);
 
+
+void phylink_rx_clk_stop_block(struct phylink *pl)
+{
+	ASSERT_RTNL();
+
+	if (pl->mac_rx_clk_stop_blocked == U8_MAX) {
+		phylink_warn(pl, "%s called too many times - ignoring\n",
+			     __func__);
+		dump_stack();
+		return;
+	}
+
+	/* Disable PHY receive clock stop if this is the first time this
+	 * function has been called and clock-stop was previously enabled.
+	 */
+	if (pl->mac_rx_clk_stop_blocked++ == 0 &&
+	    pl->mac_supports_eee_ops && pl->phydev)
+	    pl->config->eee_rx_clk_stop_enable)
+		phy_eee_rx_clock_stop(pl->phydev, false);
+}
+
+/**
+ * phylink_rx_clk_stop_unblock() - unblock PHY ability to stop receive clock
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ *
+ * All calls to phylink_rx_clk_stop_block() must be balanced with a
+ * corresponding call to phylink_rx_clk_stop_unblock() to restore the PHYs
+ * clock stop ability.
+ */
+void phylink_rx_clk_stop_unblock(struct phylink *pl)
+{
+	ASSERT_RTNL();
+
+	if (pl->mac_rx_clk_stop_blocked == 0) {
+		phylink_warn(pl, "%s called too many times - ignoring\n",
+			     __func__);
+		dump_stack();
+		return;
+	}
+
+	/* Re-enable PHY receive clock stop if the number of unblocks matches
+	 * the number of calls to the block function above.
+	 */
+	if (--pl->mac_rx_clk_stop_blocked == 0 &&
+	    pl->mac_supports_eee_ops && pl->phydev &&
+	    pl->config->eee_rx_clk_stop_enable)
+		phy_eee_rx_clock_stop(pl->phydev, true);
+}
+
 /**
  * phylink_suspend() - handle a network device suspend event
  * @pl: a pointer to a &struct phylink returned from phylink_create()
@@ -2649,18 +2699,6 @@  void phylink_resume(struct phylink *pl)
 
 	ASSERT_RTNL();
 
-	if (pl->mac_supports_eee_ops && pl->phydev) {
-		/* Explicitly configure whether the PHY is allowed to stop its
-		 * receive clock on resume to ensure that it is correctly
-		 * configured.
-		 */
-		ret = phy_eee_rx_clock_stop(pl->phydev,
-					    pl->config->eee_rx_clk_stop_enable);
-		if (ret == -EOPNOTSUPP)
-			phylink_warn(pl, "failed to set rx clock stop: %pe\n",
-				     ERR_PTR(ret));
-	}
-
 	if (test_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state)) {
 		/* Wake-on-Lan enabled, MAC handling */
 
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 08df65f6867a..249c437d6b7b 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -698,6 +698,9 @@  int phylink_pcs_pre_init(struct phylink *pl, struct phylink_pcs *pcs);
 void phylink_start(struct phylink *);
 void phylink_stop(struct phylink *);
 
+void phylink_rx_clk_stop_block(struct phylink *);
+void phylink_rx_clk_stop_unblock(struct phylink *);
+
 void phylink_suspend(struct phylink *pl, bool mac_wol);
 void phylink_resume(struct phylink *pl);