Hello,
I am trying to use Coresight drivers on Juno r0 board with 4.9 Linux sources (Linaro release 17.01 with 'latest-armlt').
I have tried the configuration with ETM as the source and ETF as the sink and it is working as expected. But with ETR as the sink, when stopping the tracing, kernel panic occurs.
The bug can be reproduced with the following steps: / # echo 1 > /sys/bus/coresight/devices/20070000.etr/enable_sink / # echo 1 > /sys/bus/coresight/devices/22040000.etm/enable_source / # echo 0 > /sys/bus/coresight/devices/22040000.etm/enable_source
Sometime the system also hangs without printing panic message.
I am attaching the log file and .config file along with this mail. From the logs, it looks like an arm SCP firmware problem. Let me know if I am missing some steps/configuration or If this is a know hardware/firmware problem with hopefully some workarounds existing.
Thanks and regards, Don Kuzhiyelil
On 25 April 2017 at 08:10, Don Kuzhiyelil dku@sysgo.com wrote:
Hello,
I am trying to use Coresight drivers on Juno r0 board with 4.9 Linux sources (Linaro release 17.01 with 'latest-armlt').
I have tried the configuration with ETM as the source and ETF as the sink and it is working as expected. But with ETR as the sink, when stopping the tracing, kernel panic occurs.
The bug can be reproduced with the following steps: / # echo 1 > /sys/bus/coresight/devices/20070000.etr/enable_sink / # echo 1 > /sys/bus/coresight/devices/22040000.etm/enable_source / # echo 0 > /sys/bus/coresight/devices/22040000.etm/enable_source
Sometime the system also hangs without printing panic message.
I am attaching the log file and .config file along with this mail. From the logs, it looks like an arm SCP firmware problem. Let me know if I am missing some steps/configuration or If this is a know hardware/firmware problem with hopefully some workarounds existing.
Hi Don,
From the above snapshot I assume you are using CS from sysFS. Note
that if you want to use Perf you will need to use the perf-opencsd-4.9 branch we have on gitHub.
Yes, the PC and LR registers in the core dump do point to a FW problem. Make sure you have the latest FW installed on the platform. We had to do work in that area to make sure the power controller doesn't switch off components while they are in use.
Thanks, Mathieu
Thanks and regards, Don Kuzhiyelil
CoreSight mailing list CoreSight@lists.linaro.org https://lists.linaro.org/mailman/listinfo/coresight
On 25.04.2017 16:29, Mathieu Poirier wrote:
On 25 April 2017 at 08:10, Don Kuzhiyelil dku@sysgo.com wrote:
Hello,
I am trying to use Coresight drivers on Juno r0 board with 4.9 Linux sources (Linaro release 17.01 with 'latest-armlt').
I have tried the configuration with ETM as the source and ETF as the sink and it is working as expected. But with ETR as the sink, when stopping the tracing, kernel panic occurs.
The bug can be reproduced with the following steps: / # echo 1 > /sys/bus/coresight/devices/20070000.etr/enable_sink / # echo 1 > /sys/bus/coresight/devices/22040000.etm/enable_source / # echo 0 > /sys/bus/coresight/devices/22040000.etm/enable_source
Sometime the system also hangs without printing panic message.
I am attaching the log file and .config file along with this mail. From the logs, it looks like an arm SCP firmware problem. Let me know if I am missing some steps/configuration or If this is a know hardware/firmware problem with hopefully some workarounds existing.
Hi Don,
From the above snapshot I assume you are using CS from sysFS. Note that if you want to use Perf you will need to use the perf-opencsd-4.9 branch we have on gitHub.
Yes, the PC and LR registers in the core dump do point to a FW problem. Make sure you have the latest FW installed on the platform. We had to do work in that area to make sure the power controller doesn't switch off components while they are in use.
Thanks, Mathieu
Hi Mathieu,
Many thanks for the quick reply. Yes, we were running a very old SCP firmware (v1.10.0). After updating to the latest Linaro release (SCP v1.21.0), the problem is gone and I could use Coresight via sysfs interface and with perf.
Do you recommend using 4.9 kernel for Coresight drivers or should I use the 4.10 or mainline. Are there any serious issues with Coresight drivers/SCPI driver/.. on 4.9 that is fixed on the later releases?
that if you want to use Perf you will need to use the perf-opencsd-4.9 branch we have on gitHub.
I tried the perf built from this branch and it looks quite promising. I have some doubts about the usage and the way perf uses the Coresight devices. I will probably ask them in a different mail. Is there any other documentation available on perf using Coresight other than this: https://github.com/Linaro/OpenCSD/blob/master/HOWTO.md
Thanks and regards, Don Kuzhiyelil
Thanks and regards, Don Kuzhiyelil
CoreSight mailing list CoreSight@lists.linaro.org https://lists.linaro.org/mailman/listinfo/coresight
On 27 April 2017 at 11:42, Don Kuzhiyelil dku@sysgo.com wrote:
On 25.04.2017 16:29, Mathieu Poirier wrote:
On 25 April 2017 at 08:10, Don Kuzhiyelil dku@sysgo.com wrote:
Hello,
I am trying to use Coresight drivers on Juno r0 board with 4.9 Linux sources (Linaro release 17.01 with 'latest-armlt').
I have tried the configuration with ETM as the source and ETF as the sink and it is working as expected. But with ETR as the sink, when stopping the tracing, kernel panic occurs.
The bug can be reproduced with the following steps: / # echo 1 > /sys/bus/coresight/devices/20070000.etr/enable_sink / # echo 1 > /sys/bus/coresight/devices/22040000.etm/enable_source / # echo 0 > /sys/bus/coresight/devices/22040000.etm/enable_source
Sometime the system also hangs without printing panic message.
I am attaching the log file and .config file along with this mail. From the logs, it looks like an arm SCP firmware problem. Let me know if I am missing some steps/configuration or If this is a know hardware/firmware problem with hopefully some workarounds existing.
Hi Don,
From the above snapshot I assume you are using CS from sysFS. Note that if you want to use Perf you will need to use the perf-opencsd-4.9 branch we have on gitHub.
Yes, the PC and LR registers in the core dump do point to a FW problem. Make sure you have the latest FW installed on the platform. We had to do work in that area to make sure the power controller doesn't switch off components while they are in use.
Thanks, Mathieu
Hi Mathieu,
Many thanks for the quick reply. Yes, we were running a very old SCP firmware (v1.10.0). After updating to the latest Linaro release (SCP v1.21.0), the problem is gone and I could use Coresight via sysfs interface and with perf.
Do you recommend using 4.9 kernel for Coresight drivers or should I use the 4.10 or mainline.
All the kernel branches on github have the same functionality so you can use the latest that is on there. I should be able to push 4.11 by Wednesday of next week if not before.
Are there any serious issues with Coresight drivers/SCPI driver/.. on 4.9 that is fixed on the later releases?
No, everything was pushed upstream a while back.
that if you want to use Perf you will need to use the perf-opencsd-4.9 branch we have on gitHub.
When using perf the code on github is mandatory.
I tried the perf built from this branch and it looks quite promising. I have some doubts about the usage and the way perf uses the Coresight devices. I will probably ask them in a different mail.
Very well.
Is there any other documentation available on perf using Coresight other than this: https://github.com/Linaro/OpenCSD/blob/master/HOWTO.md
No - we keep everything there. Let me know if you think something is not explained properly or missing and I will make sure it is fixed.
Yours, Mathieu
Thanks and regards, Don Kuzhiyelil
Thanks and regards, Don Kuzhiyelil
CoreSight mailing list CoreSight@lists.linaro.org https://lists.linaro.org/mailman/listinfo/coresight
-
Don Kuzhiyelil -
Mathieu Poirier