From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 9FBE51A024F for ; Thu, 29 May 2014 06:29:14 +1000 (EST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) by ozlabs.org (Postfix) with ESMTP id 50FDA140093 for ; Thu, 29 May 2014 06:29:13 +1000 (EST) Date: Wed, 28 May 2014 13:32:48 -0700 From: Greg Kroah-Hartman To: Benjamin Herrenschmidt Subject: Re: [PATCH] tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick() Message-ID: <20140528203248.GA14431@kroah.com> References: <1400838066.29150.69.camel@pasglop> <1401235290.8262.9.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1401235290.8262.9.camel@pasglop> Cc: linuxppc-dev list , Jiri Slaby , Linux Kernel list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, May 28, 2014 at 10:01:30AM +1000, Benjamin Herrenschmidt wrote: > On Fri, 2014-05-23 at 19:41 +1000, Benjamin Herrenschmidt wrote: > > Some backends call hvc_kick() to wakeup the HVC thread from its > > slumber upon incoming characters. This however doesn't work > > properly because it uses msleep_interruptible() which is mostly > > immune to wake_up_process(). It will basically go back to sleep > > until the timeout is expired (only signals can really wake it). > > > > Replace it with a simple shedule_timeout_interruptible() instead, > > which may wakeup earlier every now and then but we really don't > > care in this case. > > Nobody commented ? :-) > > Greg, do you want to take this in the tty tree or can I stick it in > powerpc ? I'll take it, thanks. greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754904AbaE1U3O (ORCPT ); Wed, 28 May 2014 16:29:14 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:40695 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751308AbaE1U3N (ORCPT ); Wed, 28 May 2014 16:29:13 -0400 Date: Wed, 28 May 2014 13:32:48 -0700 From: Greg Kroah-Hartman To: Benjamin Herrenschmidt Cc: Jiri Slaby , Linux Kernel list , linuxppc-dev list Subject: Re: [PATCH] tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick() Message-ID: <20140528203248.GA14431@kroah.com> References: <1400838066.29150.69.camel@pasglop> <1401235290.8262.9.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1401235290.8262.9.camel@pasglop> 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 Wed, May 28, 2014 at 10:01:30AM +1000, Benjamin Herrenschmidt wrote: > On Fri, 2014-05-23 at 19:41 +1000, Benjamin Herrenschmidt wrote: > > Some backends call hvc_kick() to wakeup the HVC thread from its > > slumber upon incoming characters. This however doesn't work > > properly because it uses msleep_interruptible() which is mostly > > immune to wake_up_process(). It will basically go back to sleep > > until the timeout is expired (only signals can really wake it). > > > > Replace it with a simple shedule_timeout_interruptible() instead, > > which may wakeup earlier every now and then but we really don't > > care in this case. > > Nobody commented ? :-) > > Greg, do you want to take this in the tty tree or can I stick it in > powerpc ? I'll take it, thanks. greg k-h