[PATCH 0/1] coresight: fix issue with insufficient claim tags

[Mike Leach]

All CoreSight compliant components have an implementation defined number
of 0 to 8 claim tag bits in the claim tag registers.

These are used to claim the CoreSight resources by system agents.

ARM recommends implementions have 4 claim tag registers.

The CoreSight drivers implement a 2 claim tag bit protocol to allow
self hosted and external debug agents to manage access to the hardware.

However, if there are less than 2 claim tags available the protocol
incorrectly returns an error on device claim, as no checks are made.

If insufficient claim tags are present in a component then the protocol
must return success on claim / disclaim to allow components to be used
normally.

Changes read the CLAIMSET bits to establish the number of available tags,
and adjust the claim returns accordingly.

Applies to coresignt/next

Mike Leach (1):
  coresight: fix issue where coresight component has no claimtags

 drivers/hwtracing/coresight/coresight-core.c | 26 ++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-priv.h |  8 ++++++
 2 files changed, 34 insertions(+)

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2.32.0