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Message-ID: <d232392a-dadb-ec53-9613-d9b561fe1e87@arm.com>
Date:   Mon, 3 Apr 2023 10:40:11 +0100
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Subject: Re: [PATCH] perf/arm-cmn: fix regitster offset of
 CMN_MXP__CONNECT_INFO_P2-5
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To:     Mark Rutland <mark.rutland@arm.com>
Cc:     Jing Zhang <renyu.zj@linux.alibaba.com>,
        Ilkka Koskinen <ilkka@os.amperecomputing.com>,
        Will Deacon <will@kernel.org>, linux-kernel@vger.kernel.org,
        linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-perf-users@vger.kernel.org,
        Shuai Xue <xueshuai@linux.alibaba.com>,
        Zhuo Song <zhuo.song@linux.alibaba.com>,
        Ruidong Tian <tianruidong@linux.alibaba.com>
References: <1680169620-26012-1-git-send-email-renyu.zj@linux.alibaba.com>
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From:   Robin Murphy <robin.murphy@arm.com>
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On 2023-04-03 08:45, Mark Rutland wrote:
> On Thu, Mar 30, 2023 at 11:34:22AM +0100, Robin Murphy wrote:
>> On 2023-03-30 10:47, Jing Zhang wrote:
>>> In the CMN700 specification, it is described that the address offset
>>> of the mxp_device_connect_info_p0-5 register is 16'h8 + #{8*index}.
>>> Therefore, the address offset of the CMN_MXP__CONNECT_INFO_P2-5 macro
>>> defined in the code is wrong, which causes the cmn700 topology map
>>> incorrect printed in debugfs.
>>>
>>> So correct the address offset value to make the cmn700 topology map
>>> correct in debugfs.
>>>
>>> Fixes: 60d1504070c2 ("perf/arm-cmn: Support new IP features")
>>
>> Ugh, these offsets are correct for CI-700, so strictly that commit is fine.
>> What I failed to notice is that CMN-700 shuffled the mesh_port_connect_info
>> registers out of the way, so it's commit 23760a014417 which should have
>> added more handling for this difference.
> 
> I'm assuming that means that this patch breaks !CMN-700 ?
> 
> i.e. a more substantial fix is necessary, and it's not just a matter of
> changing the Fixes tag.

Yes, indeed. I have half an idea, and the plan for this week was to work 
on other CMN stuff anyway, so I'll see what I can cook up.

Cheers,
Robin.