On Tue, Apr 28, 2026 at 01:18:12PM +0100, James Clark wrote:
[...]
static int etm4_init_pm_save(struct device *dev, struct etmv4_drvdata *drvdata) { if (etm4x_is_ete(drvdata)) {
if (pm_save_enable)dev_warn_once(dev, "pm_save_enable module option is only for ETM4\n");- /*
*/
- Always do PM save for ETE. It always uses system registers
- which will be lost on CPU power down.
pm_save_enable = PARAM_PM_SAVE_SELF_HOSTED;
drvdata->pm_save = true;
pm_save_enable = coresight_loses_context_with_cpu(dev) ?PARAM_PM_SAVE_SELF_HOSTED : PARAM_PM_SAVE_NEVER;
drvdata->pm_save = coresight_loses_context_with_cpu(dev);- } else if (pm_save_enable == PARAM_PM_SAVE_SELF_HOSTED) {
drvdata->pm_save = true;- } else {
drvdata->pm_save = false;
Could we separate ETE and ETM a bit?
int cpu_pm;
cpu_pm = coresight_loses_context_with_cpu(dev) ? PARAM_PM_SAVE_SELF_HOSTED : PARAM_PM_SAVE_NEVER;
if (etm4x_is_ete(drvdata)) goto alloc_out;
/* Now this is only for ETM case */
/* Do consistency check */ if ((cpu_fw_pm == PARAM_PM_SAVE_SELF_HOSTED && pm_save_enable == PARAM_PM_SAVE_NEVER) || (cpu_fw_pm == PARAM_PM_SAVE_NEVER && pm_save_enable == PARAM_PM_SAVE_SELF_HOSTED)) dev_warn(dev, "inconsistent setting ...\n");
/* Force to use the global setting */ if (pm_save_enable != PARAM_PM_SAVE_FIRMWARE) cpu_pm = pm_save_enable;
- if (pm_save_enable != PARAM_PM_SAVE_NEVER) {
- if (drvdata->pm_save) {
would be:
if (cpu_pm == PARAM_PM_SAVE_SELF_HOSTED)
drvdata->save_state = devm_kmalloc(dev, sizeof(struct etmv4_save_state), GFP_KERNEL);@@ -2037,7 +2047,7 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata) { int ret = 0;
- if (pm_save_enable != PARAM_PM_SAVE_SELF_HOSTED)
- if (!drvdata->pm_save)
Drop "pm_save" and directly use drvdata->save_state ?
We don't need "pm_save" anyway after we apply the patch [1].
[1] http://listhost.cambridge.arm.com/pipermail/linux-eng/2026-April/030289.html