USB host: Fix lockdep warning in AMD PLL quirk
Booting latest kernel on my test machine produces a lockdep warning from the usb_amd_find_chipset_info() function: WARNING: at /data/lemmy/linux.trees.git/kernel/lockdep.c:2465 lockdep_trace_alloc+0x95/0xc2() Hardware name: Snook Modules linked in: Pid: 959, comm: work_for_cpu Not tainted 2.6.39-rc2+ #22 Call Trace: [<ffffffff8103c0d4>] warn_slowpath_common+0x80/0x98 [<ffffffff812387e6>] ? T.492+0x24/0x26 [<ffffffff8103c101>] warn_slowpath_null+0x15/0x17 [<ffffffff81068667>] lockdep_trace_alloc+0x95/0xc2 [<ffffffff810ed9ac>] slab_pre_alloc_hook+0x18/0x3b [<ffffffff810ef227>] kmem_cache_alloc_trace+0x25/0xba [<ffffffff812387e6>] T.492+0x24/0x26 [<ffffffff81238816>] pci_get_subsys+0x2e/0x73 [<ffffffff8123886c>] pci_get_device+0x11/0x13 [<ffffffff814082a9>] usb_amd_find_chipset_info+0x3f/0x18a ... It turns out that this function calls pci_get_device under a spin_lock with irqs disabled, but the pci_get_device function is only allowed in preemptible context. This patch fixes the warning by making all data-structure modifications on temporal storage and commiting this back into the visible structure at the end. While at it, this patch also moves the pci_dev_put calls out of the spinlocks because this function might sleep too. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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