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If the PHY driver uses another PHY internally (e.g. in case of eUSB2, repeaters are represented as PHYs), then it would trigger the following lockdep splat because all PHYs use a single static lockdep key and thus lockdep can not identify whether there is a dependency or not and reports a false positive. Make PHY subsystem use dynamic lockdep keys, assigning each driver a separate key. This way lockdep can correctly identify dependency graph between mutexes. ============================================ WARNING: possible recursive locking detected 6.15.0-rc7-next-20250522-12896-g3932f283970c #3455 Not tainted -------------------------------------------- kworker/u51:0/78 is trying to acquire lock: ffff0008116554f0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c but task is already holding lock: ffff000813c10cf0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&phy->mutex); lock(&phy->mutex); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by kworker/u51:0/78: #0: ffff000800010948 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x18c/0x5ec #1: ffff80008036bdb0 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1b4/0x5ec #2: ffff0008094ac8f8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x38/0x188 #3: ffff000813c10cf0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c stack backtrace: CPU: 0 UID: 0 PID: 78 Comm: kworker/u51:0 Not tainted 6.15.0-rc7-next-20250522-12896-g3932f283970c #3455 PREEMPT Hardware name: Qualcomm CRD, BIOS 6.0.240904.BOOT.MXF.2.4-00528.1-HAMOA-1 09/ 4/2024 Workqueue: events_unbound deferred_probe_work_func Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x90/0xd0 dump_stack+0x18/0x24 print_deadlock_bug+0x258/0x348 __lock_acquire+0x10fc/0x1f84 lock_acquire+0x1c8/0x338 __mutex_lock+0xb8/0x59c mutex_lock_nested+0x24/0x30 phy_init+0x4c/0x12c snps_eusb2_hsphy_init+0x54/0x1a0 phy_init+0xe0/0x12c dwc3_core_init+0x450/0x10b4 dwc3_core_probe+0xce4/0x15fc dwc3_probe+0x64/0xb0 platform_probe+0x68/0xc4 really_probe+0xbc/0x298 __driver_probe_device+0x78/0x12c driver_probe_device+0x3c/0x160 __device_attach_driver+0xb8/0x138 bus_for_each_drv+0x84/0xe0 __device_attach+0x9c/0x188 device_initial_probe+0x14/0x20 bus_probe_device+0xac/0xb0 deferred_probe_work_func+0x8c/0xc8 process_one_work+0x208/0x5ec worker_thread+0x1c0/0x368 kthread+0x14c/0x20c ret_from_fork+0x10/0x20 Fixes:3584f6392f("phy: qcom: phy-qcom-snps-eusb2: Add support for eUSB2 repeater") Fixes:e2463559ff("phy: amlogic: Add Amlogic AXG PCIE PHY Driver") Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Reviewed-by: Abel Vesa <abel.vesa@linaro.org> Reported-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/lkml/ZnpoAVGJMG4Zu-Jw@hovoldconsulting.com/ Reviewed-by: Johan Hovold <johan+linaro@kernel.org> Tested-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Link: https://lore.kernel.org/r/20250605-phy-subinit-v3-1-1e1e849e10cd@oss.qualcomm.com Signed-off-by: Vinod Koul <vkoul@kernel.org>