Re: [PATCHv8 2/5] arm64: dts: qcom: msm8998: Add Coresight support

Sai Prakash Ranjan
2019-07-18T09:14:16Z

Hi Suzuki,

On 7/18/2019 1:58 PM, Suzuki K Poulose wrote:
> Hi Sai,
>
>
>         etr@6048000 {
>> +            compatible = "arm,coresight-tmc", "arm,primecell";
>> +            reg = <0x06048000 0x1000>;
>> +
>> +            clocks = <&rpmcc RPM_SMD_QDSS_CLK>, <&rpmcc
>> RPM_SMD_QDSS_A_CLK>;
>> +            clock-names = "apb_pclk", "atclk";
>> +            arm,scatter-gather;
>
> Please could you confirm that you have tested the scatter-gather mode
> with ETR ? Either via perf/sysfs. Please could you share your results ?
> Unless verified
> this is going to be fatal for the system.
>
> Similarly for other platforms.
>

Yes I have tested with scatter-gather mode with ETR on all platforms
which I have posted via sysfs(not perf) before on previous versions of
this patch series and no issues were found. And I suppose this was
discussed in v2 of this patch series [1].

As said in one of the series initially [1], QCOM msm downstream kernels
have been using scatter gather mode and we haven't seen any fatal issues.

[1] https://patchwork.kernel.org/patch/10769535/

Thanks,
Sai