From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943254AbcJSPDu (ORCPT ); Wed, 19 Oct 2016 11:03:50 -0400 Received: from gofer.mess.org ([80.229.237.210]:58731 "EHLO gofer.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941727AbcJSPDp (ORCPT ); Wed, 19 Oct 2016 11:03:45 -0400 Date: Wed, 19 Oct 2016 10:07:19 +0100 From: Sean Young To: Nathan Zimmer Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, gregkh@linuxfoundation.org, alan@linux.intel.com Subject: Re: console issue since 3.6, console=ttyS1 hangs Message-ID: <20161019090719.GA1764@gofer.mess.org> References: <20161017144951.GA235535@stormcage.americas.sgi.com> <20161017151906.GA19082@gofer.mess.org> <20161017164140.GA35950@stormcage.americas.sgi.com> <20161018164004.GA159046@stormcage.americas.sgi.com> <20161018180518.GA28700@gofer.mess.org> <20161018192930.GA207959@stormcage.americas.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161018192930.GA207959@stormcage.americas.sgi.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 18, 2016 at 02:29:30PM -0500, Nathan Zimmer wrote: > On Tue, Oct 18, 2016 at 07:05:18PM +0100, Sean Young wrote: > > On Tue, Oct 18, 2016 at 11:40:04AM -0500, Nathan Zimmer wrote: > > > 3.7.0 > > > cat /sys/bus/pnp/drivers/serial/*/resources > > > state = active > > > io 0x2f8-0x2ff > > > irq 12 > > > dma disabled > > > > > > 3.6.0 > > > :~ # cat /sys/bus/pnp/drivers/serial/*/resources > > > cat: /sys/bus/pnp/drivers/serial/*/resources: No such file or directory > > > > irq 12 for ttyS1? That should be irq 3. The bios is putting bogus information > > in pnp. Maybe there is rubbish in the bios setup or maybe it's fixed in a > > newer bios update. > > > > So before this change, the kernel would assume irq 3. After this change, > > the kernel first uses the information in pnp to see where the serial > > port is. It gets told that it's irq 12 and presumably it runs into all > > sorts of problems then. If memory serves that's the irq for the ps/2 mouse. > > > > The interesting bit is in 3.6.0: > > > > setserial > > /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3 > > > > becomes in 3.7.0: > > > > setserial > > /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 12 > > > > You should be able to set the right irq with setserial, but obviously > > that doesn't help you if it fails in early boot. It's not immediately > > obvious to me what can be done in the kernel for this. Maybe the dmesg > > output could inspire, thanks. > > Yea the changing irq seemed weird to me too but I couldn't manage a guess to why. > > Here are the dmesgs. So with 3.6.0: > [ 2.079980] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled > [ 2.100887] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A > [ 2.101715] serial 00:04: unable to assign resources > [ 2.102174] serial: probe of 00:04 failed with error -16 The pnp probe fails for some reason. I don't understand why. With 3.7.0: > [ 2.062700] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled > [ 2.063250] serial 00:04: [io 0x02f8-0x02ff] > [ 2.063875] serial 00:04: [irq 12] > [ 2.064345] serial 00:04: [dma 18446744073709551615 disabled] > [ 2.065540] serial 00:04: activated > [ 2.086442] 00:04: ttyS1 at I/O 0x2f8 (irq = 12) is a 16550A Now the pnp probe succeeds (with broken irq from pnp). Can you please check if there is a wrong irq configured in the bios setup or if there is a bios update available? I don't know why this worked in the first place. Sean