From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: "Fu, Zhonghui" <zhonghui.fu@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, pavel@ucw.cz,
        len.brown@intel.com, linux-pm@vger.kernel.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] PM-Trace: add pm-trace support for suspending phase
Date: Thu, 12 Feb 2015 23:24:58 +0100
Message-ID: <3110302.hjQJaaphe1@vostro.rjw.lan>
User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; )
In-Reply-To: <54DC3086.5030603@linux.intel.com>
References: <54DB6A81.3040706@linux.intel.com> <5368734.2g4GXN33HR@vostro.rjw.lan> <54DC3086.5030603@linux.intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="utf-8"
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1946
Lines: 41

On Thursday, February 12, 2015 12:48:06 PM Fu, Zhonghui wrote:
> 
> On 2015/2/11 23:25, Rafael J. Wysocki wrote:
> > On Wednesday, February 11, 2015 10:43:13 PM Fu, Zhonghui wrote:
> >> From 2626594c03ca3b9884dd44073385c36f99a3651d Mon Sep 17 00:00:00 2001
> >> From: Zhonghui Fu <zhonghui.fu@linux.intel.com>
> >> Date: Wed, 11 Feb 2015 16:20:21 +0800
> >> Subject: [PATCH] PM-Trace: add pm-trace support for suspending phase
> > Can you please avoid putting the above header lines into your patches?
> >
> > The only one that may be necessary is the From: line, but that's only
> > needed if you submit from a different address.
> >
> > Also please don't send To: mailing lists.  Use CC instead.  In fact, there
> > should be *one* address in the To: field when you're submitting a patch:
> > The address of the maintainer you want to apply the patch for you.
> Thanks for your guidance, and I will re-send this patch.
> 
> >
> >> Occasionally, the system can't come back up after suspend/resume
> >> due to problems of device suspending phase. This patch make
> >> PM_TRACE infrastructure cover device suspending phase of
> >> suspend/resume process, and the information in RTC can tell
> >> developers which device suspending function make system hang.
> > Do you have any examples of when this helped and no other debug methods did?
> >
> > It seems odd to me that no one has ever asked for this for several years and
> > now you need it.
> We ever run into some system hang during suspending some devices on BayTrail-T
> platform such as DMA, audio, etc. So, extending PM-Trace to suspend phase should
> be helpful.

Well, did you actually use this particular patch for debugging that?

Rafael

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/