Thomas Monjalon <tho...@monjalon.net> writes: > 10/10/2017 18:00, Aaron Conole: >> Shreyansh Jain <shreyansh.j...@nxp.com> writes: >> >> > Hello Don, >> > >> > On Monday 09 October 2017 11:51 PM, Don Provan wrote: >> >>> -----Original Message----- >> >>> From: Shreyansh Jain [mailto:shreyansh.j...@nxp.com] >> >>> Sent: Monday, October 09, 2017 4:10 AM >> >>> To: Jan Blunck <jblu...@infradead.org>; Thomas Monjalon >> >>> <tho...@monjalon.net> >> >>> Cc: dev <dev@dpdk.org>; Hemant Agrawal <hemant.agra...@nxp.com> >> >>> Subject: Re: [dpdk-dev] [PATCH] eal: bus scan and probe never fail >> >>> >> >>> ... >> >>> This is where I have disagreement/doubt. >> >>> Reporting error code from rte_bus_scan would do two things: >> >>> >> >>> 1. rte_eal_init is not designed to ignore/log-only these errors - it >> >>> would quit initialization. (But, this can be changed) >> >>> 2. What should rte_eal_init do with this error? rte_bus_scan would have >> >>> already printed the problematic bus->scan() failure. >> >> >> >> These practical problems confirm to me that the failure of a bus >> >> scan is more of a strategic issue: when asking "which devices can >> >> I use?", "none" is a perfectly valid answer that does not seem >> >> like an error to me even when a failed bus scan is the reason for >> >> that answer. >> > >> > I agree with this. >> > >> >> >> >> From the application's point of view, the potential error here >> >> is that the device it wants to use isn't available. I don't see that >> >> either the init function or the probe function will have enough >> >> information to understand that application-level problem, so >> >> they should leave it to the application to detect it. >> > >> > I think I understand you comment but just want to cross check again: >> > Scan or probe error should simply be ignored by EAL layer and let the >> > application take stance when it detects that the device it was looking >> > for is missing. Is my understanding correct? >> > >> > I am trying to come a conclusion so that this patch can either be >> > modified or pushed as it is. If the above understanding is correct, I >> > don't see any changes required in the patch. >> >> Does it make sense to introduce a way to query the results of the >> various bus types for their status? That way we can give the relevant >> information to the application if it wants, and make the bus scanning >> code *always* succeed? This version shouldn't be an ABI breakage, >> either (confirm?). >> >> half-baked below (not tested or suitable - just an example): > > We are going to need notification callbacks for scan and probe anyway. > I think errors could be also notified with callbacks?
Definitely. That's part of my half-baked patch. Call the error check function and get a callback. There's probably a better way to do it than my patch.
