Re: [PATCH v4 7/7] OMAP3630: PM: Erratum i583: disable coreoff if < ES1.2

Santosh Shilimkar wrote, on 12/20/2010 12:51 AM:
[...]

quoted

+
+	/*
+	 * Erratum i583: implementation for ES rev<  Es1.2 on 3630. We
cannot
+	 * enable OFF mode in a stable form for previous revisions.
+	 * we disable C7 state as a result.
+	 */
+	if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) {
+		omap3_power_states[OMAP3_STATE_C7].valid = 0;
+		cpuidle_params_table[OMAP3_STATE_C7].valid = 0;

WARN_ONCE in IDLE also would be good.

quoted

+	}

this state will not be active anyways as enable_off_mode is 0 by default.

quoted

  }

  struct cpuidle_driver omap3_idle_driver = {

diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 92ef400..9032d09 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h

@@ -87,6 +87,7 @@ extern unsigned int omap24xx_cpu_suspend_sz;
  extern unsigned int omap34xx_cpu_suspend_sz;

  #define PM_RTA_ERRATUM_i608		(1<<  0)
+#define PM_SDRC_WAKEUP_ERRATUM_i583	(1<<  1)

  #if defined(CONFIG_PM)&&  defined(CONFIG_ARCH_OMAP3)
  extern u16 pm34xx_errata;

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 21cd36e..7faea55 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c

@@ -928,12 +928,28 @@ void omap3_pm_off_mode_enable(int enable)
  		state = PWRDM_POWER_RET;

  #ifdef CONFIG_CPU_IDLE
-	omap3_cpuidle_update_states(state, state);
+	/*
+	 * Erratum i583: implementation for ES rev<  Es1.2 on 3630. We

cannot
+	 * enable OFF mode in a stable form for previous revisions,

restrict

quoted

+	 * instead to RET
+	 */
+	if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
+		omap3_cpuidle_update_states(state, PWRDM_POWER_RET);
+	else
+		omap3_cpuidle_update_states(state, state);
  #endif

  	list_for_each_entry(pwrst,&pwrst_list, node) {
-		pwrst->next_state = state;
-		omap_set_pwrdm_state(pwrst->pwrdm, state);
+		if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)&&
+				pwrst->pwrdm == core_pwrdm&&
+				state == PWRDM_POWER_OFF) {
+			pwrst->next_state = PWRDM_POWER_RET;
+			pr_err("%s: Core OFF disabled due to errata

i583\n",
Shoud we do this in every iteration or just WARN_ONCE do ??

every time off mode is enabled? this path is not exercised for every cpu 
idle/suspend iteration.

-- 
Regards,
Nishanth Menon