diff mbox series

[net-next,v1] net: phy: phy_device: fix PHY WOL enabled, PM failed to suspend

Message ID 20240704123200.603654-1-youwan@nfschina.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series [net-next,v1] net: phy: phy_device: fix PHY WOL enabled, PM failed to suspend | expand

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netdev/series_format success Single patches do not need cover letters
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 success Errors and warnings before: 839 this patch: 839
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 846 this patch: 846
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 success Errors and warnings before: 846 this patch: 846
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 22 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 40 this patch: 40
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-07-05--06-00 (tests: 695)

Commit Message

Youwan Wang July 4, 2024, 12:32 p.m. UTC
If the PHY of the mido bus is enabled with Wake-on-LAN (WOL),
we cannot suspend the PHY. Although the WOL status has been
checked in phy_suspend(), returning -EBUSY(-16) would cause
the Power Management (PM) to fail to suspend. Since
phy_suspend() is an exported symbol (EXPORT_SYMBOL),
timely error reporting is needed. Therefore, an additional
check is performed here. If the PHY of the mido bus is enabled
with WOL, we skip calling phy_suspend() to avoid PM failure.

Thank you all for your analysis.
I am using the Linux kernel version 6.6, the current system is
utilizing ACPI firmware. However, in terms of configuration,
the system only includes MAC layer configuration while lacking
PHY configuration. Furthermore, it has been observed that the
phydev->attached_dev is NULL, phydev is "stmmac-0:01", it not
attached, but it will affect suspend and resume. The actually
attached "stmmac-0:00" will not dpm_run_callback():
mdio_bus_phy_suspend().

The current modification is solely aimed at ensuring that PHY
have WOL enabled but are not attached are calling phy_suspend()

log:
[    5.932502] YT8521 Gigabit Ethernet stmmac-0:00: attached PHY driver
(mii_bus:phy_addr=stmmac-0:00, irq=POLL)
[    5.932512] YT8521 Gigabit Ethernet stmmac-0:01: attached PHY driver
(mii_bus:phy_addr=stmmac-0:01, irq=POLL)
[   24.566289] YT8521 Gigabit Ethernet stmmac-0:00: yt8521_read_status,
link down, media: UTP

log:
[  322.631362] OOM killer disabled.
[  322.631364] Freezing remaining freezable tasks
[  322.632536] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[  322.632540] printk: Suspending console(s) (use no_console_suspend to debug)
[  322.633052] YT8521 Gigabit Ethernet stmmac-0:01:
PM: dpm_run_callback(): mdio_bus_phy_suspend+0x0/0x110 [libphy] returns -16
[  322.633071] YT8521 Gigabit Ethernet stmmac-0:01:
PM: failed to suspend: error -16
[  322.669699] PM: Some devices failed to suspend, or early wake event detected
[  322.669949] OOM killer enabled.
[  322.669951] Restarting tasks ... done.
[  322.671008] random: crng reseeded on system resumption
[  322.671014] PM: suspend exit

log:
[  260.814763] YT8521 Gigabit Ethernet stmmac-0:01:
PM: dpm_run_callback():mdio_bus_phy_resume+0x0/0x160 [libphy] returns -95
[  260.814782] YT8521 Gigabit Ethernet stmmac-0:01:
PM: failed to resume: error -95

Signed-off-by: Youwan Wang <youwan@nfschina.com>
---
 drivers/net/phy/phy_device.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 2ce74593d6e4..0564decf701f 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -270,6 +270,7 @@  static DEFINE_MUTEX(phy_fixup_lock);
 
 static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 {
+	struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
 	struct device_driver *drv = phydev->mdio.dev.driver;
 	struct phy_driver *phydrv = to_phy_driver(drv);
 	struct net_device *netdev = phydev->attached_dev;
@@ -277,6 +278,15 @@  static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
 	if (!drv || !phydrv->suspend)
 		return false;
 
+	/* If the PHY on the mido bus is not attached but has WOL enabled
+	 * we cannot suspend the PHY.
+	 */
+	phy_ethtool_get_wol(phydev, &wol);
+	phydev->wol_enabled = !!(wol.wolopts);
+	if (!netdev && phydev->wol_enabled &&
+	    !(phydrv->flags & PHY_ALWAYS_CALL_SUSPEND))
+		return false;
+
 	/* PHY not attached? May suspend if the PHY has not already been
 	 * suspended as part of a prior call to phy_disconnect() ->
 	 * phy_detach() -> phy_suspend() because the parent netdev might be the