We've had some people trying to track a problem for months revolving
around a system hanging at shutdown, and last thing they see being a
message from mpt3sas about a reset. They quickly bisected down to the
commit below, and reverted it made the problem go away for the
customer.
b424eaa1b51c ("scsi: mpt3sas: Transition IOC to Ready state during shutdown")
I got asked to look at something since I recently at another issue
that involved mpt3sas at shutdown, so I was looking through the
history, saw this commit being mentined. Looking at it, I'm not sure
why it is doing what is doing.
It says it is to perform a soft reset, but that was already happening before this commit via:
scsih_shutdown -> mpt3sas_base_detach -> mpt3sas_base_free_resources -> _base_make_ioc_ready(ioc, SOFT_RESET);
The original submission [1] had the following commit message:
"During shutdown just move the IOC state to Ready state
by issuing MUR. No need to free any IOC memory pools."
But is now skipping more than not freeing the memory pools. It no
longer frees memory that was kalloc'd, it doesn't unmap something that
was iomapped, it no longer cleans up the fault reset workqueue, and no
longer calls the pci cleanup code. It also no longer does the things
it moved to scsih_shutdown under the pci access mutex, nor uses the if
condition that was in mpt3sas_base_free_resources.
[1] https://lore.kernel.org/r/20210705145951.32258-1-sreekanth.reddy@xxxxxxxxxxxx
Am I missing something, and what the commit does here is really okay?
Regards,
Jerry
