> On Apr 21, 2017, at 2:20 PM, Bart Van Assche <bart.vanass...@sandisk.com> > wrote: > > On Fri, 2017-04-21 at 14:13 -0700, Song Liu wrote: >> On the other hand, some devices do long latency IO during deletion, >> for example, sd_shutdown() may do sync cache and/or start_stop. >> It is not necessary for these commands to run in series. > > Have you noticed my patch series that makes sd_shutdown() submit the > SYNCHRONIZE CACHE command asynchronously? Have you tried whether that > patch series would be a good alternative? > > Thanks, > > Bart.
The asynchronous SYNCHRONIZE CACHE will not help our use case, where the latency comes from sd_start_stop_device(). Seems it is not easy to make the START STOP UNIT command async. Thanks, Song