From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Randy.Dunlap" Subject: Re: [PATCH 2/2] Fix console handling during suspend/resume Date: Tue, 13 Jun 2006 17:06:09 -0700 Message-ID: <20060613170609.3291ce36.rdunlap@xenotime.net> References: <200606131620.45156.david-b@pacbell.net> <200606141000.12260.ncunningham@linuxmail.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200606141000.12260.ncunningham@linuxmail.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: Nigel Cunningham Cc: david-b@pacbell.net, torvalds@osdl.org, linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org On Wed, 14 Jun 2006 10:00:08 +1000 Nigel Cunningham wrote: > Hi. > = > On Wednesday 14 June 2006 09:46, Linus Torvalds wrote: > > On Tue, 13 Jun 2006, David Brownell wrote: > > > Here's a related patch (well, "hack") I found helpful ... specificall= y to > > > help let _serial_ consoles be more useful. > > > > I just checked. > > > > I think exactly _two_ of the six machines I have around my desk have > > serial ports, and of those two, one is permanently turned off because i= t's > > old, noisy, and just not interesting. > > > > Maybe I'm more progressive than most, but I personally consider serial > > lines pretty much dead. > = > Usb to serial converters are not completely unheard of, though. My old = > omnibook even came with one. It's the one bit I still use :) and usb serial-console works, although not during early init (it has to wait for the usb subsystem to be ready). > > > Although I must say I like Nigel's "BDI-2000 per developer" hack bett= er. > > > Even though not all boxes can hook up to a JTAG module. :( > > > > Umm. Even more importantly, I don't think the JTAG interfaces for PC's = are > > necessarily even available. There is read-out logic for ARM's and embed= ded > > PPC, but have you ever seen anything for something non-embedded? > = > Yeah. Sort of kills that idea, doesn't it? > = > > A really useful trick the PPC people use was to put the firewire > > controller into "anybody can read" mode, and use it as a kernel debugger > > when it basically becomes a remote memory DMA engine. I used that to de= bug > > some kernel hangs, and it was very nice. > > > > However, that won't survive a power event, so it might be useful to deb= ug > > suspend problems, but generally not resume problems. > = > Since just about every problem occurs at resume time, it really does seem= to = > me to be the case that we have to use the rtc. Great idea, by the way. --- ~Randy