Re: [PATCH v2 08/28] coresight: etm4x: Remove the state_needs_restore flag

[Yeoreum Yun <yeoreum.yun@arm.com>]

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

> When the restore flow is invoked, it means no error occurred during the
> save phase. Otherwise, if any errors happened while saving the context,
> the function would return an error and abort the suspend sequence.
>
> Therefore, the state_needs_restore flag is unnecessary. The save and
> restore functions are changed to check two conditions:
>
> 1) The global flag pm_save_enable is SELF_HOSTED mode;
> 2) The device is in active mode (non DISABLED).
>
> Signed-off-by: Leo Yan <leo.yan@arm.com>
> ---
>  drivers/hwtracing/coresight/coresight-etm4x-core.c | 14 ++++++++------
>  drivers/hwtracing/coresight/coresight-etm4x.h      |  2 --
>  2 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 6cd76a2527cf11752963a7cb1b3b0e9a8be241f0..1faf8614366f38eea4909152558fe8e69730bde4 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -1981,8 +1981,6 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
>  		goto out;
>  	}
>
> -	drvdata->state_needs_restore = true;
> -
>  	/*
>  	 * Power can be removed from the trace unit now. We do this to
>  	 * potentially save power on systems that respect the TRCPDCR_PU
> @@ -2000,11 +1998,14 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
>  {
>  	int ret = 0;
>
> +	if (pm_save_enable != PARAM_PM_SAVE_SELF_HOSTED)
> +		return 0;
> +
>  	/*
>  	 * Save and restore the ETM Trace registers only if
>  	 * the ETM is active.
>  	 */
> -	if (coresight_get_mode(drvdata->csdev) && drvdata->save_state)
> +	if (coresight_get_mode(drvdata->csdev))
>  		ret = __etm4_cpu_save(drvdata);
>  	return ret;
>  }
> @@ -2093,8 +2094,6 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
>  	if (!drvdata->skip_power_up)
>  		etm4x_relaxed_write32(csa, state->trcpdcr, TRCPDCR);
>
> -	drvdata->state_needs_restore = false;
> -
>  	/*
>  	 * As recommended by section 4.3.7 ("Synchronization when using the
>  	 * memory-mapped interface") of ARM IHI 0064D
> @@ -2120,7 +2119,10 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
>
>  static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
>  {
> -	if (drvdata->state_needs_restore)
> +	if (pm_save_enable != PARAM_PM_SAVE_SELF_HOSTED)
> +		return;
> +
> +	if (coresight_get_mode(drvdata->csdev))
>  		__etm4_cpu_restore(drvdata);
>  }
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index 4d32605a84ce91eae2101cd83cad5f5317e2638a..06438ed1071478cd5c1a143c6ef58a926d6992fb 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -978,7 +978,6 @@ struct etmv4_save_state {
>   *		in EL2. Otherwise, 0.
>   * @config:	structure holding configuration parameters.
>   * @save_state:	State to be preserved across power loss
> - * @state_needs_restore: True when there is context to restore after PM exit
>   * @skip_power_up: Indicates if an implementation can skip powering up
>   *		   the trace unit.
>   * @paused:	Indicates if the trace unit is paused.
> @@ -1032,7 +1031,6 @@ struct etmv4_drvdata {
>  	u64				trfcr;
>  	struct etmv4_config		config;
>  	struct etmv4_save_state		*save_state;
> -	bool				state_needs_restore;
>  	bool				skip_power_up;
>  	bool				paused;
>  	DECLARE_BITMAP(arch_features, ETM4_IMPDEF_FEATURE_MAX);
>
> --
> 2.34.1
>

--
Sincerely,
Yeoreum Yun