From mboxrd@z Thu Jan 1 00:00:00 1970 From: willy@linux.intel.com (Matthew Wilcox) Date: Tue, 4 Aug 2015 09:40:00 -0400 Subject: what time does host will re-used the prplist memory region. In-Reply-To: References: Message-ID: <20150804134000.GB13681@linux.intel.com> On Tue, Aug 04, 2015@11:29:47AM +0800, HavenYang wrote: > It says the SQhead indicate Submission Queue entries may be re-used, but it not say the PRPlist related to this command may be re-used or not, I confused. > > my question is: > 1. from host side,?what is the condition can host re-used the prplist memory region for a host command, SQHead or command complete? The host can only reuse the PRP list memory when the command has been completed. The device is entitled to use the PRP list throughout execution of the command. > 2. from device side, what is the condition to update SQHead, fetched command head(simple) or fetched all prp from prplist(complex)? The first; the host only takes this as an indication that it can reuse the SQ entry.