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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💿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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.