usb: xhci: tegra: fix sleep in atomic call

In the Linux kernel, the following vulnerability has been resolved:

usb: xhci: tegra: fix sleep in atomic call

When we set the dual-role port to Host mode, we observed the following

splat:

[ 167.057718] BUG: sleeping function called from invalid context at

include/linux/sched/mm.h:229

[ 167.057872] Workqueue: events tegra_xusb_usb_phy_work

[ 167.057954] Call trace:

[ 167.057962] dump_backtrace+0x0/0x210

[ 167.057996] show_stack+0x30/0x50

[ 167.058020] dump_stack_lvl+0x64/0x84

[ 167.058065] dump_stack+0x14/0x34

[ 167.058100] __might_resched+0x144/0x180

[ 167.058140] __might_sleep+0x64/0xd0

[ 167.058171] slab_pre_alloc_hook.constprop.0+0xa8/0x110

[ 167.058202] __kmalloc_track_caller+0x74/0x2b0

[ 167.058233] kvasprintf+0xa4/0x190

[ 167.058261] kasprintf+0x58/0x90

[ 167.058285] tegra_xusb_find_port_node.isra.0+0x58/0xd0

[ 167.058334] tegra_xusb_find_port+0x38/0xa0

[ 167.058380] tegra_xusb_padctl_get_usb3_companion+0x38/0xd0

[ 167.058430] tegra_xhci_id_notify+0x8c/0x1e0

[ 167.058473] notifier_call_chain+0x88/0x100

[ 167.058506] atomic_notifier_call_chain+0x44/0x70

[ 167.058537] tegra_xusb_usb_phy_work+0x60/0xd0

[ 167.058581] process_one_work+0x1dc/0x4c0

[ 167.058618] worker_thread+0x54/0x410

[ 167.058650] kthread+0x188/0x1b0

[ 167.058672] ret_from_fork+0x10/0x20

The function tegra_xusb_padctl_get_usb3_companion eventually calls

tegra_xusb_find_port and this in turn calls kasprintf which might sleep

and so cannot be called from an atomic context.

Fix this by moving the call to tegra_xusb_padctl_get_usb3_companion to

the tegra_xhci_id_work function where it is really needed.