On Tue, Jan 30, 2018 at 11:07:16PM +0100, Nikola Ciprich wrote: > Hello dear linux-serial developers, > > I'v been struggling for some time to get brainboxes multiport serial > card working under 4.14 kernel.. it's working fine for me under 4.4 > (just using some setserial magic), but I need to switch to newer kernel. > > Under 4.14, when I try to setup the card, system either hangs, or just > spits backtrace and hangs when I try to use some of the configured ports > > After some googling, I noticed some reports of multiport serial cards problem > between 4.8 and 4.9 (without resolution), so I tested it, and really, 4.8 > works fine, 4.9 always hangs during setserial setup (I'm not 100% sure it's > the same problem I have in 4.14 though). > > I've bisected it to > > commit b3b57646186400d4f54652ab7bbf55f5764d9467 > Author: Rob Herring <robh@xxxxxxxxxx> > Date: Mon Aug 22 17:39:09 2016 -0500 > > tty: serial_core: convert uart_open to use tty_port_open > before this patch, it works, after it, it doesn't. My question is, does > somebody remember some issues being fixed after this one? Yeah, that commit lead to some issues, of which at least some have been fixed in mainline. But a related new report came in just a couple of weeks ago, see below. > It's problematic to revert even with 4.9, and even worse with 4.14, so > before I try digging deeper into it, I thougt I'd just try my luck asking > here :) > > I'd be very gratefull for any hints Can you give this patch this a try: https://lkml.kernel.org/r/20180111175726.g2f2r7hx376yq73t@xxxxxxxxxxxxx We should probably get that one backported to stable while fixing the remaining issues with that incomplete tty-port conversion. Johan -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
