RE: [PATCH 7/8] coresight: cti: Remove hw_enabled flag

[Mike Leach]

Hi Leo,


> -----Original Message-----
> From: Leo Yan <leo.yan@xxxxxxx>
> Sent: Monday, February 9, 2026 6:01 PM
> To: Suzuki Poulose <Suzuki.Poulose@xxxxxxx>; Mike Leach
> <Mike.Leach@xxxxxxx>; James Clark <james.clark@xxxxxxxxxx>; Alexander
> Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; Mathieu Poirier
> <mathieu.poirier@xxxxxxxxxx>; Tingwei Zhang <quic_tingwei@xxxxxxxxxxx>;
> Yingchao Deng <yingchao.deng@xxxxxxxxxxxxxxxx>; Jie Gan
> <jie.gan@xxxxxxxxxxxxxxxx>
> Cc: coresight@xxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Leo Yan <Leo.Yan@xxxxxxx>
> Subject: [PATCH 7/8] coresight: cti: Remove hw_enabled flag
> 
> The enable_req_count field already tracks whether the CTI device is
> enabled.  A non-zero value indicates that the device is active, the
> hw_enabled flag is redundant if so.
> 

Minor nit - removal of this flag actually started in the previous patch. If respinning might be worth combining this and the previous one.

> Remove hw_enabled and update cti_is_active() to check enable_req_count.
> Replace open-coded enable_req_count checks with cti_is_active().
> 
> Signed-off-by: Leo Yan <leo.yan@xxxxxxx>
> ---
>  drivers/hwtracing/coresight/coresight-cti-core.c  | 11 ++---------
>  drivers/hwtracing/coresight/coresight-cti-sysfs.c |  2 +-
>  drivers/hwtracing/coresight/coresight-cti.h       |  4 +---
>  3 files changed, 4 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c
> b/drivers/hwtracing/coresight/coresight-cti-core.c
> index
> 3b3b851a018851a8656eba64e638c61f3d04b99f..a7acee27d0aa2c842733f
> 62b7ff88a4c296b51cc 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-core.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-core.c
> @@ -90,7 +90,7 @@ static int cti_enable_hw(struct cti_drvdata *drvdata)
>  	guard(raw_spinlock_irqsave)(&drvdata->spinlock);
> 
>  	/* no need to do anything if enabled */
> -	if (config->hw_enabled)
> +	if (cti_is_active(config))
>  		goto cti_state_unchanged;
> 
>  	/* claim the device */
> @@ -100,8 +100,6 @@ static int cti_enable_hw(struct cti_drvdata *drvdata)
> 
>  	cti_write_all_hw_regs(drvdata);
> 
> -	config->hw_enabled = true;
> -
>  cti_state_unchanged:
>  	drvdata->config.enable_req_count++;
>  	return 0;
> @@ -116,22 +114,17 @@ static int cti_disable_hw(struct cti_drvdata
> *drvdata)
>  	guard(raw_spinlock_irqsave)(&drvdata->spinlock);
> 
>  	/* don't allow negative refcounts, return an error */
> -	if (!drvdata->config.enable_req_count)
> +	if (!cti_is_active(config))
>  		return -EINVAL;
> 
>  	/* check refcount - disable on 0 */
>  	if (--drvdata->config.enable_req_count > 0)
>  		return 0;
> 
> -	/* no need to do anything if disabled */
> -	if (!config->hw_enabled)
> -		return 0;
> -
>  	CS_UNLOCK(drvdata->base);
> 
>  	/* disable CTI */
>  	writel_relaxed(0, drvdata->base + CTICONTROL);
> -	config->hw_enabled = false;
> 
>  	coresight_disclaim_device_unlocked(csdev);
>  	CS_LOCK(drvdata->base);
> diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> index
> 9ab586a5c9a4fd2a64c542aaaaa625e2299edd62..9ef44956ebdc7781717d7
> 73fa014165989df2048 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> @@ -84,7 +84,7 @@ static ssize_t enable_show(struct device *dev,
>  	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
> 
>  	scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
> -		enable_req = drvdata->config.enable_req_count;
> +		enable_req = cti_is_active(&drvdata->config);
> 
>  	return sprintf(buf, "%d\n", !!enable_req);
>  }
> diff --git a/drivers/hwtracing/coresight/coresight-cti.h
> b/drivers/hwtracing/coresight/coresight-cti.h
> index
> c858847a5b80036fb48180ff7fbbfe684028cb89..fbb48eb5b0b6a571235d7f
> ecb2c13fc294d8ba50 100644
> --- a/drivers/hwtracing/coresight/coresight-cti.h
> +++ b/drivers/hwtracing/coresight/coresight-cti.h
> @@ -121,7 +121,6 @@ struct cti_device {
>   * @nr_ctm_channels: number of available CTM channels - from ID register.
>   * @asicctl_impl: true if asicctl is implemented.
>   * @enable_req_count: CTI is enabled alongside >=1 associated devices.
> - * @hw_enabled: true if hw is currently enabled.
>   * @trig_in_use: bitfield of in triggers registered as in use.
>   * @trig_out_use: bitfield of out triggers registered as in use.
>   * @trig_out_filter: bitfield of out triggers that are blocked if filter
> @@ -144,7 +143,6 @@ struct cti_config {
> 
>  	/* cti enable control */
>  	int enable_req_count;
> -	bool hw_enabled;
> 
>  	/* registered triggers and filtering */
>  	u32 trig_in_use;
> @@ -238,7 +236,7 @@ const char *cti_plat_get_node_name(struct
> fwnode_handle *fwnode);
>  /* Check if a cti device is enabled */
>  static inline bool cti_is_active(struct cti_config *cfg)
>  {
> -	return cfg->hw_enabled;
> +	return !!cfg->enable_req_count;
>  }
> 
>  #endif  /* _CORESIGHT_CORESIGHT_CTI_H */
> 
> --
> 2.34.1

Reviewed-by: Mike Leach <mike.leach@xxxxxxx>