From: Josh Karabin <gkarabin@vocollect.com>
To: Peter Barada <peterb@logicpd.com>
Cc: "Syed Mohammed, Khasim" <khasim@ti.com>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>
Subject: Re: JTAG debugging of the kernel
Date: Fri, 15 Aug 2008 14:57:31 -0400 [thread overview]
Message-ID: <48A5D19B.1050407@vocollect.com> (raw)
In-Reply-To: <1218823096.24975.108.camel@blackhole>
Peter Barada wrote:
> On Fri, 2008-08-15 at 23:04 +0530, Syed Mohammed, Khasim wrote:
>>> -----Original Message-----
>>> From: linux-omap-owner@vger.kernel.org [mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Peter
>>> Barada
>>> Any suggestions on what can cause the JTAG to stop working after the
>>> kernel starts?
>>>
>> I think you should disable Power Management. Which kernel are you using now?
>
> 2.6.22.18. I'm planning to move to 2.6.26 after the dust settles...
>
> I'll try w/o power management, but any idea why power management might
> affect JTAG?
The guy I share an office with (who's out on vacation) worked through
this with their tech support, who suggested replacing WFI instructions
with NOPs.
Look at cpu_v7_do_idle in arch/arm/mm/proc-v7.S. Changing the WFI to a
NOP did the trick for him.
Presumably power management was off, but even WFI (wait for interrupt)
put the CPU in a state that wasn't handled by the BDI firmware at the
time. I'm not sure if they resolved the issue in a later firmware
update or not. We didn't think the workaround was worthy of a Kconfig
option - hopefully updated firmware for the BDI box will address the issue.
- Josh
next prev parent reply other threads:[~2008-08-15 18:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-15 15:03 JTAG debugging of the kernel Peter Barada
2008-08-15 17:34 ` Syed Mohammed, Khasim
2008-08-15 17:58 ` Peter Barada
2008-08-15 18:57 ` Josh Karabin [this message]
2008-08-18 18:47 ` Peter Barada
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=48A5D19B.1050407@vocollect.com \
--to=gkarabin@vocollect.com \
--cc=khasim@ti.com \
--cc=linux-omap@vger.kernel.org \
--cc=peterb@logicpd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.