CVS commit: src/sys/dev/ic

["Jaromir Dolecek" <jdolecek%netbsd.org@localhost>]

Module Name:    src
Committed By:   jdolecek
Date:           Fri Mar 16 18:49:18 UTC 2018

Modified Files:
        src/sys/dev/ic: nvme.c nvmevar.h

Log Message:
stop using q_nccbs_avail for deciding whether there are available ccbs;
no need to maintain a counter _and_ q_ccb_list

this fixes deadlock when all ccbs happen to be taken before completion
interrupt - nvme_q_complete() increased q_nccbs_avail only after
processing all the completed commands, by then there was nothing
left to actually kick the disk queue again into action

this also fixes ccb leak on command errors e.g. with bus_dmamem_alloc()
or bus_dmamel_load() - q_nccbs_avail was never decreased on the error path

fixes PR kern/52769 by Martin Husemann, thanks to Paul Goyette
for testing


To generate a diff of this commit:
cvs rdiff -u -r1.32 -r1.33 src/sys/dev/ic/nvme.c
cvs rdiff -u -r1.13 -r1.14 src/sys/dev/ic/nvmevar.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.