Hi guys,
On 2020-05-28 14:16, Sai Prakash Ranjan wrote:
Hi folks,
I was trying to enable SMMU translation for coresight TMC ETR component via "iommus" property on SC7180 SoC. And on enabling the trace, I observe random softlockups everytime. For enabling trace, I just select ETR as the sink and ETM as the source via sysfs and immediately start seeing lockups. I have looked from the hardware point of view and there is no errata as such and it works fine on downstream kernel which is very old - 4.14 kernel. This is reproducible even with KASAN disabled as well. Also I have dumped other CPU stacks as well during softlockup via adding dump_stack in ipi_cpu_stop and and no interesting logs there as other cpus are idle.
As an update, this turned out to be due to firmware misconfiguration.
Thanks, Sai
On Sat, 30 May 2020 at 04:23, Sai Prakash Ranjan saiprakash.ranjan@codeaurora.org wrote:
Hi guys,
On 2020-05-28 14:16, Sai Prakash Ranjan wrote:
Hi folks,
I was trying to enable SMMU translation for coresight TMC ETR component via "iommus" property on SC7180 SoC. And on enabling the trace, I observe random softlockups everytime. For enabling trace, I just select ETR as the sink and ETM as the source via sysfs and immediately start seeing lockups. I have looked from the hardware point of view and there is no errata as such and it works fine on downstream kernel which is very old - 4.14 kernel. This is reproducible even with KASAN disabled as well. Also I have dumped other CPU stacks as well during softlockup via adding dump_stack in ipi_cpu_stop and and no interesting logs there as other cpus are idle.
As an update, this turned out to be due to firmware misconfiguration.
Many thanks for the follow-up.
Mathieu
Thanks, Sai
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Mathieu Poirier -
Sai Prakash Ranjan