jsauer/torvalds-linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-01-12 01:20:14 +00:00
Code

coresight: etm4x: Remove the state_needs_restore flag

Browse Source 
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).

Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20251111-arm_coresight_power_management_fix-v6-8-f55553b6c8b3@arm.com
This commit is contained in:
Leo Yan 2025-11-11 18:58:42 +00:00 committed by Suzuki K Poulose
parent a5e6f584da
commit 9e9182cab5
2 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/hwtracing/coresight/coresight-etm4x-core.c
View File

@ -1966,8 +1966,6 @@ 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
@ -1985,11 +1983,14 @@ 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;
}
@ -2079,8 +2080,6 @@ 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
@ -2099,7 +2098,10 @@ 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);
}

2
drivers/hwtracing/coresight/coresight-etm4x.h
View File

@ -980,7 +980,6 @@ 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.
@ -1036,7 +1035,6 @@ 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);