On 2020-04-26 09:24, Rafael J. Wysocki wrote: > On Friday, April 24, 2020 5:40:16 AM CEST Dexuan Cui wrote: >> Currently the kernel threads are not frozen in software_resume(), so >> between dpm_suspend_start(PMSG_QUIESCE) and resume_target_kernel(), >> system_freezable_power_efficient_wq can still try to submit SCSI >> commands and this can cause a panic since the low level SCSI driver >> (e.g. hv_storvsc) has quiesced the SCSI adapter and can not accept >> any SCSI commands: https://lkml.org/lkml/2020/4/10/47 >> >> At first I posted a fix (https://lkml.org/lkml/2020/4/21/1318) trying >> to resolve the issue from hv_storvsc, but with the help of >> Bart Van Assche, I realized it's better to fix software_resume(), >> since this looks like a generic issue, not only pertaining to SCSI. >> >> Cc: Bart Van Assche <bvanassche@xxxxxxx> >> Cc: stable@xxxxxxxxxxxxxxx >> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> >> --- >> kernel/power/hibernate.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c >> index 86aba8706b16..30bd28d1d418 100644 >> --- a/kernel/power/hibernate.c >> +++ b/kernel/power/hibernate.c >> @@ -898,6 +898,13 @@ static int software_resume(void) >> error = freeze_processes(); >> if (error) >> goto Close_Finish; >> + >> + error = freeze_kernel_threads(); >> + if (error) { >> + thaw_processes(); >> + goto Close_Finish; >> + } >> + >> error = load_image_and_restore(); >> thaw_processes(); >> Finish: > > Applied as a fix for 5.7-rc4, thanks! Hi Rafael, What is not clear to me is how kernel threads are thawed after load_image_and_restore() has finished? Should a comment perhaps be added above the freeze_kernel_threads() call that explains how thaw_kernel_threads() is invoked after load_image_and_restore() has finished? Thanks, Bart.
