linux-kernel - Re: [PATCH 1/3] arm64: dts: qcom: sdm845: Add Coresight support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190114153509.GA29374@xps15>
Date:   Mon, 14 Jan 2019 08:35:09 -0700
From:   Mathieu Poirier <mathieu.poirier@...aro.org>
To:     saiprakash.ranjan@...eaurora.org
Cc:     Rob Herring <robh+dt@...nel.org>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Leo Yan <leo.yan@...aro.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Andy Gross <andy.gross@...aro.org>,
        David Brown <david.brown@...aro.org>,
        devicetree@...r.kernel.org, Mark Rutland <mark.rutland@....com>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Vivek Gautam <vivek.gautam@...eaurora.org>,
        Sibi Sankar <sibis@...eaurora.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, linux-arm-msm-owner@...r.kernel.org
Subject: Re: [PATCH 1/3] arm64: dts: qcom: sdm845: Add Coresight support

On Sat, Jan 12, 2019 at 06:21:00PM +0530, saiprakash.ranjan@...eaurora.org wrote:
> Hi Mathieu,
> 
> > > +
> > > +	etm@...0000 {
> > > +		compatible = "arm,coresight-etm4x", "arm,primecell";
> > > +		arm,primecell-periphid = <0x000bb95d>;
> > 
> > I'm a little curious as to why you need to bypass the normal AMBA bus
> > discovery
> > method by forcing the peripheral ID.  Tracers don't show up the way
> > other
> > coresight devices do at boot time?
> > 
> 
> Yes on some Qcom SoC's like SDM845 and also on some previous ones, for
> ETM(only) amba bus discovery method fails because of wrong pid read from the
> registers. So we have to force this primecell peripheral ids to probe etm.

Ok, if that is the case please add a comment to explain the situation.
Otherwise someone will assuredly ask again in the future.

Mathieu


> 
> - Sai
> 
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of
> Code Aurora Forum, hosted by The Linux Foundation