linux-kernel - Re: [PATCH v3 0/7] coresight: Clear self hosted claim tag on probe

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Message-ID: <Z9w44Qq7Mo+kTWZ9@e129823.arm.com>
Date: Thu, 20 Mar 2025 15:48:49 +0000
From: Yeoreum Yun <yeoreum.yun@....com>
To: James Clark <james.clark@...aro.org>
Cc: Suzuki K Poulose <suzuki.poulose@....com>,
	Mike Leach <mike.leach@...aro.org>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Maxime Coquelin <mcoquelin.stm32@...il.com>,
	Alexandre Torgue <alexandre.torgue@...s.st.com>, leo.yan@....com,
	coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-stm32@...md-mailman.stormreply.com
Subject: Re: [PATCH v3 0/7] coresight: Clear self hosted claim tag on probe

On Thu, Mar 20, 2025 at 02:34:09PM +0000, James Clark wrote:
> I've gotten stuck a few times with unusable Coresight after a warm boot
> due to lingering claim tags, especially when testing the Coresight
> panic patchsets.
>
> This change does some tidy ups, adds some debug messages and clears the
> self hosted claim tag on probe. The last two commits are unrelated
> tidyups but they touch some of the same functions so to avoid extra
> conflicts I'm including them here.
>
> This gets as far as fixing the claim tag issue, but there is some other
> state not being cleared on probe that results in the following error.
> This can be fixed up as a later change:
>
>   coresight tmc_etf0: timeout while waiting for TMC to be Ready
>   coresight tmc_etf0: Failed to enable : TMC is not ready
>
> Changes in v3:
> - Collapse rename and locked/unlocked addition commits of
>   coresight_clear_self_claim_tag() so we don't change the name twice.
> - Make coresight_clear_self_claim_tag() a bit more generic by only
>   doing UNLOCK for MMIO devices (although there is no use of this right
>   now)
> - Link to v2: https://lore.kernel.org/r/20250318-james-coresight-claim-tags-v2-0-e9c8a9cde84e@linaro.org
>
> Changes in v2:
>  * Revert most of the interface changes, just call
>    coresight_clear_self_claim_tag() directly. This is possible because
>    we're not doing the read first, so it has fewer knock on effects.
>  * Split out the change to add struct cs_access to etm3x
>  * Add another warning for racing with external debugger
>
> --
> 2.34.1
>
> ---
> James Clark (7):
>       coresight: Convert tag clear function to take a struct cs_access
>       coresight: Only check bottom two claim bits
>       coresight: Add claim tag warnings and debug messages
>       coresight: etm3x: Convert raw base pointer to struct coresight access
>       coresight: Clear self hosted claim tag on probe
>       coresight: Remove inlines from static function definitions
>       coresight: Remove extern from function declarations
>
>  drivers/hwtracing/coresight/coresight-catu.c       | 12 +--
>  drivers/hwtracing/coresight/coresight-core.c       | 87 ++++++++++++++--------
>  drivers/hwtracing/coresight/coresight-cti-core.c   |  2 +
>  drivers/hwtracing/coresight/coresight-etb10.c      |  4 +-
>  drivers/hwtracing/coresight/coresight-etm.h        |  6 +-
>  drivers/hwtracing/coresight/coresight-etm3x-core.c | 28 +++----
>  .../hwtracing/coresight/coresight-etm3x-sysfs.c    |  8 +-
>  drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++-
>  .../hwtracing/coresight/coresight-etm4x-sysfs.c    |  4 +-
>  drivers/hwtracing/coresight/coresight-funnel.c     |  1 +
>  drivers/hwtracing/coresight/coresight-platform.c   | 26 +++----
>  drivers/hwtracing/coresight/coresight-priv.h       | 20 ++---
>  drivers/hwtracing/coresight/coresight-replicator.c |  3 +-
>  drivers/hwtracing/coresight/coresight-stm.c        |  6 +-
>  .../coresight/coresight-syscfg-configfs.c          |  2 +-
>  drivers/hwtracing/coresight/coresight-tmc-core.c   |  9 ++-
>  drivers/hwtracing/coresight/coresight-tmc-etr.c    | 16 ++--
>  drivers/hwtracing/coresight/coresight-trbe.c       | 18 ++---
>  include/linux/coresight.h                          | 40 +++++-----
>  19 files changed, 168 insertions(+), 134 deletions(-)
> ---
> base-commit: 5442d22da7dbff3ba8c6720fc6f23ea4934d402d
> change-id: 20250317-james-coresight-claim-tags-ae1461f1f5e0
>
> Best regards,
> --
> James Clark <james.clark@...aro.org>

Look good to me

Reviewed-by: Yeoreum Yun <yeoreum.yun@....com>