On Thursday, July 06, 2017 08:08:03 PM Hans de Goede wrote: > Hi, > > On 06-07-17 19:11, Andy Shevchenko wrote: > > On Thu, 2017-07-06 at 18:49 +0200, Hans de Goede wrote: > >> At least on the UP board SBC both PWMs are enabled leading to us > >> trying to add the same pwm_lookup twice, which leads to the following: > >> > >> [ 0.902224] list_add double add: new=ffffffffb8efd400, > >> prev=ffffffffb8efd400, next=ffffffffb8eeede0. > >> [ 0.912466] ------------[ cut here ]------------ > >> [ 0.917624] kernel BUG at lib/list_debug.c:31! > >> [ 0.922588] invalid opcode: 0000 [#1] SMP > >> ... > >> [ 1.027450] Call Trace: > >> [ 1.030185] pwm_add_table+0x4c/0x90 > >> [ 1.034181] bsw_pwm_setup+0x1a/0x20 > >> [ 1.038175] acpi_lpss_create_device+0xfe/0x420 > >> ... > >> > >> This commit fixes this by only calling pwm_add_table for the first > >> PWM controller (which is the one used for the backlight). > >> > > > > Thanks, my comment below. > > > > For the quick fix I agree on this: > > Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > Thank you. > > Rafael, can we get this added to 4.13 soonish please ? One of the 2 > commits this fixes has been causing trouble for some users since 4.11.3. Should be possible. Thanks, Rafael