Re: [RFC/PATCH] mwifiex: Driver - Firmware Glitches

From: James Cameron <quozl@laptop.org>
To: Florian Achleitner <flo@fopen.at>
Cc: Amitkumar Karwar <akarwar@marvell.com>,
	Avinash Patil <patila@marvell.com>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	Maithili Hinge <maithili@marvell.com>
Subject: Re: [RFC/PATCH] mwifiex: Driver - Firmware Glitches
Date: Thu, 23 Apr 2015 18:43:09 +1000	[thread overview]
Message-ID: <20150423084309.GL2147@us.netrek.org> (raw)
In-Reply-To: <2079721.JMnuuxDd1J@r90b40zn>

On Thu, Apr 23, 2015 at 10:33:02AM +0200, Florian Achleitner wrote:
> On Friday 17 April 2015 02:45:02 Amitkumar Karwar wrote:
> > Known firmware issues are command timeout and wakeup failure. They
> > are not specific to SDIO. As Avinash mentioned earlier, we need to
> > check CONFIG_MMC_DEBUG enbled dmesg logs for "write iomem (1)
> > failed: -110" issue.
> 
> Thx.
> A kernel with CONFIG_MMC_DEBUG is running since 6 days on 4 devices,
> but nothing valuable captured yet. Unfortunately, it looks like the
> debugging code modifies the timing, such that the failure doesn't
> occur..

Yes, I've seen something similar last year, when I began to add
instrumentation code the problems became less reproducible.

So in my situation either there was a race condition with the
firmware, or a signal integrity problem on the SDIO.

I wasn't able to go into full signal integrity work at the time.

I also have rather hazy memory of which particular problem I was
working on.  ;-)

Perhaps you might review the effects of CONFIG_MMC_DEBUG and remove
some of it?

-- 
James Cameron
http://quozl.linux.org.au/