From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [Kgdb-bugreport] [PATCH 2.6.20-rc7] 8139too KGDBoE fix Date: Fri, 23 Feb 2007 11:13:54 -0800 Message-ID: <20070223111354.2e25db9d@freekitty> References: <200701312144.56497.sshtylyov@ru.mvista.com> <45DDBD96.10000@ru.mvista.com> <45DDC7C0.8050100@ru.mvista.com> <200702231238.40474.amitkale@linsyssoft.com> <45DF2E20.305@mvista.com> <20070223110451.44066f09@freekitty> <45DF3BDC.2070806@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Mark Huth , "Amit S. Kale" , netdev@vger.kernel.org, Mithlesh Thukral , Vitaly Wool To: Sergei Shtylyov Return-path: Received: from smtp.osdl.org ([65.172.181.24]:54439 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933184AbXBWTOb (ORCPT ); Fri, 23 Feb 2007 14:14:31 -0500 In-Reply-To: <45DF3BDC.2070806@ru.mvista.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, 23 Feb 2007 22:09:16 +0300 Sergei Shtylyov wrote: > Hello. > > Stephen Hemminger wrote: > > >>>This thread came up on kgdb-bugreport mailing list. Could you please suggest > >>>us what's the correct way of fixing this problem? > > >>>1. When running a kgdb on RTL8139 ethernet interface: 8139too driver prints > >>>too many "Out-of-sync dirty pointer" messages on console and gdb can't > >>>connect to kgdb stub. These messages can be suppressed, though it still > >>>results in connection failures frequently. > > >>We think this comes from calling the driver while the queue is stopped. > >>Drivers should not do horrible things when hard start is called with the > >>queue stopped, but unfortunately, at this time, at least some drivers > >>do explode or complain under that condition. > > > The kernel is built on a set of assumptions about calling context. Your > > out of tree code is violating one of them. Why not check for stopped queue > > and do some action to try and clear it, that is what netconsole does. > > The queue can't be stopped when the netpoll traffic trapping is enabled > (cause this effectively bypasses queue control), So, the stopped queue > indoication doesn't work also -- *that* is the problem. It's not at all > specific to KGBoE -- only to traffic trapping. You can't ask a device to send a packet when it has no resources. -- Stephen Hemminger