Hi Stephan,
On 18/06/2019 21:26, Stephan Gerhold wrote:
Hi,
I'm trying to run mainline Linux on a smartphone with MSM8916 SoC.
It works surprisingly well, but the coresight devices seem to cause the
following crash shortly after userspace starts:
Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP
...
In this case I'm using a simple device tree similar to apq8016-sbc,
but it also happens using something as simple as msm8916-mtp.dts
on this particular device.
(Attached: dmesg log with msm8916-mtp.dts and arm64 defconfig)
I can avoid the crash and boot without any further problems by disabling
every coresight device defined in msm8916.dtsi, e.g.:
tpiu@820000 { status = "disabled"; };
...
I don't have any use for coresight at the moment,
but it seems somewhat odd to put this in the device specific dts.
Any idea what could be causing this crash?
This is mostly due to the missing power domain support. The CoreSight
components are usually in a debug power domain. So unless that is turned on,
(either by specifying proper power domain ids for power management protocol
supported by the firmware OR via other hacks - e.g, connecting a DS-5 to
keep the debug power domain turned on , this works on Juno -).
I'm not sure if this is a device-specific issue or possibly some kind of
configuration problem.
Or is this feature only working on development boards?
Cheers
Suzuki
