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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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c825bab0ce
This patch fixes one lockdep warning[1] inside usb_stor_pre_reset. If the current configuration includes multiple mass storage interfaces, the 'AA' lockdep warning will be triggered since the lock class of 'us->dev_mutex' is acquired two times in .reset path. It isn't a real deadlock, so just take the lockdep_set_class annotation to remove the warning. [1], lockdep warning log :[ INFO: possible recursive locking detected ] :3.3.0-0.rc5.git3.1.fc17.x86_64 #1 Tainted: G W :--------------------------------------------- :usb-storage/14846 is trying to acquire lock: : (&(us->dev_mutex)){+.+.+.}, at: [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage] :but task is already holding lock: : (&(us->dev_mutex)){+.+.+.}, at: [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage] :other info that might help us debug this: : Possible unsafe locking scenario: : CPU0 : ---- : lock(&(us->dev_mutex)); : lock(&(us->dev_mutex)); : *** DEADLOCK *** : May be due to missing lock nesting notation :2 locks held by usb-storage/14846: : #0: (&__lockdep_no_validate__){......}, at: [<ffffffff8147e6a5>] usb_lock_device_for_reset+0x95/0x100 : #1: (&(us->dev_mutex)){+.+.+.}, at: [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage] :stack backtrace: :Pid: 14846, comm: usb-storage Tainted: G W 3.3.0-0.rc5.git3.1.fc17.x86_64 #1 :Call Trace: : [<ffffffff810cbdaf>] __lock_acquire+0x168f/0x1bb0 : [<ffffffff81021083>] ? native_sched_clock+0x13/0x80 : [<ffffffff810210f9>] ? sched_clock+0x9/0x10 : [<ffffffff810210f9>] ? sched_clock+0x9/0x10 : [<ffffffff810a2975>] ? sched_clock_local+0x25/0xa0 : [<ffffffff810cc9a1>] lock_acquire+0xa1/0x1e0 : [<ffffffffa0481c0c>] ? usb_stor_pre_reset+0x1c/0x20 [usb_storage] : [<ffffffff81699c86>] mutex_lock_nested+0x76/0x3a0 : [<ffffffffa0481c0c>] ? usb_stor_pre_reset+0x1c/0x20 [usb_storage] : [<ffffffffa0481c0c>] ? usb_stor_pre_reset+0x1c/0x20 [usb_storage] : [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage] : [<ffffffff8148184d>] usb_reset_device+0x7d/0x190 : [<ffffffffa048119c>] usb_stor_port_reset+0x7c/0x80 [usb_storage] : [<ffffffffa0481234>] usb_stor_invoke_transport+0x94/0x560 [usb_storage] : [<ffffffff810cd3b2>] ? mark_held_locks+0xb2/0x130 : [<ffffffff8169dbd0>] ? _raw_spin_unlock_irq+0x30/0x50 : [<ffffffffa047fe3e>] usb_stor_transparent_scsi_command+0xe/0x10 [usb_storage] : [<ffffffffa0481ae3>] usb_stor_control_thread+0x173/0x280 [usb_storage] : [<ffffffffa0481970>] ? fill_inquiry_response+0x20/0x20 [usb_storage] : [<ffffffff8108a3f7>] kthread+0xb7/0xc0 : [<ffffffff816a7d34>] kernel_thread_helper+0x4/0x10 : [<ffffffff8169e0f4>] ? retint_restore_args+0x13/0x13 : [<ffffffff8108a340>] ? kthread_worker_fn+0x1a0/0x1a0 : [<ffffffff816a7d30>] ? gs_change+0x13/0x13 Reported-By: Dave Jones <davej@redhat.com> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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.. | ||
atm | ||
c67x00 | ||
class | ||
core | ||
dwc3 | ||
early | ||
gadget | ||
host | ||
image | ||
misc | ||
mon | ||
musb | ||
otg | ||
renesas_usbhs | ||
serial | ||
storage | ||
wusbcore | ||
Kconfig | ||
Makefile | ||
README | ||
usb-common.c | ||
usb-skeleton.c |
To understand all the Linux-USB framework, you'll use these resources: * This source code. This is necessarily an evolving work, and includes kerneldoc that should help you get a current overview. ("make pdfdocs", and then look at "usb.pdf" for host side and "gadget.pdf" for peripheral side.) Also, Documentation/usb has more information. * The USB 2.0 specification (from www.usb.org), with supplements such as those for USB OTG and the various device classes. The USB specification has a good overview chapter, and USB peripherals conform to the widely known "Chapter 9". * Chip specifications for USB controllers. Examples include host controllers (on PCs, servers, and more); peripheral controllers (in devices with Linux firmware, like printers or cell phones); and hard-wired peripherals like Ethernet adapters. * Specifications for other protocols implemented by USB peripheral functions. Some are vendor-specific; others are vendor-neutral but just standardized outside of the www.usb.org team. Here is a list of what each subdirectory here is, and what is contained in them. core/ - This is for the core USB host code, including the usbfs files and the hub class driver ("khubd"). host/ - This is for USB host controller drivers. This includes UHCI, OHCI, EHCI, and others that might be used with more specialized "embedded" systems. gadget/ - This is for USB peripheral controller drivers and the various gadget drivers which talk to them. Individual USB driver directories. A new driver should be added to the first subdirectory in the list below that it fits into. image/ - This is for still image drivers, like scanners or digital cameras. ../input/ - This is for any driver that uses the input subsystem, like keyboard, mice, touchscreens, tablets, etc. ../media/ - This is for multimedia drivers, like video cameras, radios, and any other drivers that talk to the v4l subsystem. ../net/ - This is for network drivers. serial/ - This is for USB to serial drivers. storage/ - This is for USB mass-storage drivers. class/ - This is for all USB device drivers that do not fit into any of the above categories, and work for a range of USB Class specified devices. misc/ - This is for all USB device drivers that do not fit into any of the above categories.