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?
