FYI, we noticed the below changes on

https://github.com/0day-ci/linux Sudip-Mukherjee/Revert-Staging-panel-usleep_range-is-preferred-over-udelay/20160123-172052
commit a9ddaac527316789b14647b823878ca305827b55 ("Revert "Staging: panel: usleep_range is preferred over udelay"")

The commit FIXED the following bugs in the parent commit.

[   11.176305] BUG: scheduling while atomic: swapper/1/0x00000002
[   11.176789] CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.0-rc8 #1
[   11.177245]  00000000 00000000 cb06bd44 c180fb84 cb06bd60 c11e0a5f c3f8659c cb0672a8
[   11.177961]  00000001 00000002 00000002 cb06bd84 c3a06fcf 00000002 00000000 8cae9974
[   11.178664]  cb067000 00000001 cb06c000 cb067000 cb06bd94 c3a090a5 00000001 cb06bda8
[   11.179360] Call Trace:
[   11.179565]  [<c180fb84>] dump_stack+0x32/0x4e
[   11.179922]  [<c11e0a5f>] __schedule_bug+0xaf/0xe0
[   11.180296]  [<c3a06fcf>] __schedule+0xff/0x2090
[   11.180670]  [<c3a090a5>] schedule+0xa5/0x120
[   11.181008]  [<c3a11aef>] schedule_hrtimeout_range_clock+0x3af/0x470
[   11.181493]  [<c124fb60>] ? __hrtimer_init+0xb0/0xb0
[   11.181931]  [<c3a11bcd>] schedule_hrtimeout_range+0x1d/0x30
[   11.182361]  [<c3a11069>] usleep_range+0x69/0x90
[   11.182732]  [<c3029701>] lcd_write_cmd_p8+0x61/0x110
[   11.183138]  [<c3026fe1>] lcd_init_display+0x51/0x260
[   11.183553]  [<c302c3e6>] panel_attach+0x1396/0x1bd0
[   11.183960]  [<c1357b7d>] ? __free_pages+0xbd/0xd0
[   11.184327]  [<c1357bf5>] ? free_pages+0x65/0x80
[   11.184696]  [<c13f4d7e>] ? slob_free_pages+0x5e/0x70
[   11.185085]  [<c13f4f2c>] ? slob_free+0x19c/0xbd0
[   11.185447]  [<c257fc10>] ? driver_detach+0x60/0x60
[   11.185838]  [<c257fc74>] port_check+0x64/0x80
[   11.186179]  [<c259ed99>] bus_for_each_dev+0xf9/0x1a0
[   11.186565]  [<c25802fe>] __parport_register_driver+0x1ce/0x200
[   11.187037]  [<c257fc10>] ? driver_detach+0x60/0x60
[   11.187411]  [<c4c09622>] panel_init_module+0x489/0x568
[   11.187821]  [<c4c09199>] ? bcm2048_i2c_driver_init+0x2d/0x2d
[   11.188261]  [<c4b3af71>] do_one_initcall+0x24f/0x3fe
[   11.188697]  [<c4b3b49d>] ? kernel_init_freeable+0x37d/0x559
[   11.189128]  [<c4b3b4cb>] kernel_init_freeable+0x3ab/0x559
[   11.189557]  [<c3a0200b>] kernel_init+0x1b/0x280
[   11.189931]  [<c3a14888>] ret_from_kernel_thread+0x20/0x34
[   11.190373]  [<c3a01ff0>] ? rest_init+0x110/0x110


Thanks,
Ying Huang