> On 2/14/22 22:03, Kiwoong Kim wrote: > > The benefit that I think is not blocking dev cmd during submitting a > scsi cmd. > > Hi Kiwoong, > > Both ufshcd_exec_dev_cmd() and previous versions of > ufshcd_queuecommand() obtain a reader lock on the clock scaling lock so > concurrent submission of both command types is allowed. I'm not aware of > any version of the UFS driver that serializes device commands against SCSI > commands. > > Additionally, please take a look at commit 8d077ede48c1 ("scsi: ufs: > Optimize the command queueing code"). That patch removes the clock scaling > lock from ufshcd_queuecommand(). > > Thanks, > > Bart. Okay, I got it.