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authorRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2023-09-18 14:25:36 +0100
committerPaolo Abeni <pabeni@redhat.com>2023-09-19 17:03:44 +0200
commit6a23c555f7eb436d6799533675ffa179db3d5834 (patch)
tree82fa6d93e2be0d4a5da8dd13a9e099a734243981 /drivers/net/phy/phy.c
parent1964aacfaed526c7faa4bdc8fedb0f24ff566bdd (diff)
net: phy: fix regression with AX88772A PHY driver
Marek reports that a deadlock occurs with the AX88772A PHY used on the ASIX USB network driver: asix 1-1.4:1.0 (unnamed net_device) (uninitialized): PHY [usb-001:003:10] driver [Asix Electronics AX88772A] (irq=POLL) Asix Electronics AX88772A usb-001:003:10: attached PHY driver(mii_bus:phy_addr=usb-001:003:10, irq=POLL) asix 1-1.4:1.0 eth0: register 'asix' at usb-12110000.usb-1.4, ASIX AX88772 USB 2.0 Ethernet, a2:99:b6:cd:11:eb asix 1-1.4:1.0 eth0: configuring for phy/internal link mode ============================================ WARNING: possible recursive locking detected 6.6.0-rc1-00239-g8da77df649c4-dirty #13949 Not tainted -------------------------------------------- kworker/3:3/71 is trying to acquire lock: c6c704cc (&dev->lock){+.+.}-{3:3}, at: phy_start_aneg+0x1c/0x38 but task is already holding lock: c6c704cc (&dev->lock){+.+.}-{3:3}, at: phy_state_machine+0x100/0x2b8 This is because we now consistently call phy_process_state_change() while holding phydev->lock, but the AX88772A PHY driver then goes on to call phy_start_aneg() which tries to grab the same lock - causing deadlock. Fix this by exporting the unlocked version, and use this in the PHY driver instead. Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Fixes: ef113a60d0a9 ("net: phy: call phy_error_precise() while holding the lock") Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/E1qiEFs-007g7b-Lq@rmk-PC.armlinux.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'drivers/net/phy/phy.c')
-rw-r--r--drivers/net/phy/phy.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 93a8676dd8d8..a5fa077650e8 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -981,7 +981,7 @@ static int phy_check_link_status(struct phy_device *phydev)
* If the PHYCONTROL Layer is operating, we change the state to
* reflect the beginning of Auto-negotiation or forcing.
*/
-static int _phy_start_aneg(struct phy_device *phydev)
+int _phy_start_aneg(struct phy_device *phydev)
{
int err;
@@ -1002,6 +1002,7 @@ static int _phy_start_aneg(struct phy_device *phydev)
return err;
}
+EXPORT_SYMBOL(_phy_start_aneg);
/**
* phy_start_aneg - start auto-negotiation for this PHY device