From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: Forced HW_BREAKPOINT
Date: Wed, 1 Dec 2010 09:54:46 -0000 [thread overview]
Message-ID: <004a01cb913d$c9c1e070$5d45a150$@deacon@arm.com> (raw)
In-Reply-To: <4CF58F22.6070803@ti.com>
Hi Cyril,
> I am running an ARM1176JZ-S based SoC, on which HW breakpoints do not
> seem to function for some reason.
What are the symptoms that you are seeing? The 1176 has debug architecture
v6.1 so it should be supported by the code.
> Unfortunately the current Kconfig forces HW_BREAKPOINT if PERF_EVENTS is
> enabled on ARMV6 (commit 19852e59002fbba1c2c6ba0f154095a37ad2ac03):
>
> > + select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V7))
>
> As a result, I am unable to use the PMU for OProfile, without having hw
> breakpoints barf at boot. Is there any dependency between h/w
> breakpoints and PMU that I am missing? If not, does H/W breakpoints
> have be forced here?
The hw_breakpoint code depends on 1.) perf and 2.) hardware debug capabilities.
Since all v6 and v7 cores are supported (at least, everything should fail
gracefully if something is awry) then I don't see the point in not having it
enabled. However, if this is causing your board to break during boot we
should either fix it or allow it to be turned off.
Can you give me some more details about how it breaks please as I don't
have an 1176 that I can get my hands on?
Thanks,
Will
next prev parent reply other threads:[~2010-12-01 9:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-30 23:56 Forced HW_BREAKPOINT Cyril Chemparathy
2010-12-01 9:54 ` Will Deacon [this message]
2010-12-01 16:17 ` Cyril Chemparathy
2010-12-01 16:28 ` Will Deacon
2010-12-01 16:48 ` Cyril Chemparathy
2010-12-01 17:32 ` Will Deacon
2010-12-01 20:14 ` Cyril Chemparathy
2010-12-02 9:37 ` Will Deacon
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='004a01cb913d$c9c1e070$5d45a150$@deacon@arm.com' \
--to=will.deacon@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).