From mboxrd@z Thu Jan 1 00:00:00 1970 From: "George Spelvin" Subject: Re: 3.8-rc regression with pps-ldisc due to 70ece7a731 Date: 6 Feb 2013 14:45:14 -0500 Message-ID: <20130206194514.16104.qmail@science.horizon.com> References: <1360166020.3298.42.camel@thor.lan> Return-path: Received: from science.horizon.com ([71.41.210.146]:11023 "HELO science.horizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756226Ab3BFTpP (ORCPT ); Wed, 6 Feb 2013 14:45:15 -0500 In-Reply-To: <1360166020.3298.42.camel@thor.lan> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux@horizon.com, peter@hurleysoftware.com Cc: jslaby@suse.cz, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org > Tight coupling is what caused this to break in the first place -- I > don't think tighter coupling is the right answer. Agreed. But given that n_tty already knows there are wrappers, it would have been possible to find a cleaner way to access an "aux pointer" in the tty structure, if that's what was desired. > You are not supposed to receive ldisc->dcd_change() calls outside > the open()/close() pair. Yes, I figured that out. I was wondering because I couldn't see any way that the serial interrupt hander was blocked or masked, but then I figured out that it's not, but instead the TTY_LDISC flag is used. At the time the open() method is called, the flag is cleared, which makes tty_ldisc_ref() return NULL, which prevents calling the ldisc methods. > In the patch series I sent, I changed the BUG_ON() to WARN_ON_ONCE(). > Please reply to that patch with the snipped kernel log output if it > warns in your testing and we'll go from there. I really doubt it will. The entire code change and comment was just caution on my part. >> (Have I mentioned how ANNOYING it is when the kernel dumps more than >> 50 lines of crash message to the console screen and then locks >> the keyboard so I can't scroll back?) > netconsole on 2nd machine (see Documentation/networking/netconsole.txt) Oh, that survives interrupt crashes? Thank you!