RE: [PATCH 06/17] OMAP3: PM: Added next state check for IVA2, USB and PER into idle loop

Tero.Kristo
2009-10-16T13:37:08Z

>-----Original Message-----
>From: ext Sripathy, Vishwanath [mailto:vishwanath.bs@ti.com]
>Sent: 16 October, 2009 16:16
>To: Kristo Tero (Nokia-D/Tampere); linux-omap@vger.kernel.org
>Subject: RE: [PATCH 06/17] OMAP3: PM: Added next state check
>for IVA2, USB and PER into idle loop
>
>
> >
> >-----Original Message-----
> >From: linux-omap-owner@vger.kernel.org
>[mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Tero Kristo
> >Sent: Friday, October 16, 2009 5:49 AM
> >To: linux-omap@vger.kernel.org
> >Subject: [PATCH 06/17] OMAP3: PM: Added next state check for
>IVA2, USB and PER into idle loop
> >
> >From: Tero Kristo <tero.kristo@nokia.com>
> >
> >This is needed to prevent core from entering off mode if one
>of the IVA2,
> >USB or PER powerdomains are going to stay at least in
>retention state.
> >If this is not done, a powerdomain waking from RET may access core
> >domain which has just been reset.
> >
>From PRCM HW point of view, if any of non core domains do not
>enter OFF mode, then Core cannot enter off mode. So I do not
>understand why you want to do this change.

It appears that at least if IVA2 domain is in retention, core can and will enter off. The PER domain clock check can be used to prevent unnecessary PER domain context save/restores also.

>
> >Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
> >---
> > arch/arm/mach-omap2/pm34xx.c | 36
>+++++++++++++++++++++++++++++++-----
> > 1 files changed, 31 insertions(+), 5 deletions(-)
> >
> >diff --git a/arch/arm/mach-omap2/pm34xx.c
>b/arch/arm/mach-omap2/pm34xx.c
> >index 588ab79..3e5ae14 100644
> >--- a/arch/arm/mach-omap2/pm34xx.c
> >+++ b/arch/arm/mach-omap2/pm34xx.c
> >@@ -85,6 +85,13 @@ u32 voltage_off_while_idle;
> > OMAP3430_ST_DES1_MASK)
> > #define CORE_IDLEST3_ALL (\
> > OMAP3430ES2_ST_USBTLL_MASK|OMAP3430ES2_ST_CPEFUSE_MASK)
> >+#define PER_IDLEST_ALL (\
> >+ OMAP3430_ST_WDT3_MASK|OMAP3430_ST_MCBSP4_MASK|\
> >+ OMAP3430_ST_MCBSP3_MASK|OMAP3430_ST_MCBSP2_MASK|\
> >+ OMAP3430_ST_GPT9_MASK|OMAP3430_ST_GPT8_MASK|\
> >+ OMAP3430_ST_GPT7_MASK|OMAP3430_ST_GPT6_MASK|\
> >+ OMAP3430_ST_GPT5_MASK|OMAP3430_ST_GPT4_MASK|\
> >+ OMAP3430_ST_GPT3_MASK|OMAP3430_ST_GPT2_MASK)
> >
> > struct power_state {
> > struct powerdomain *pwrdm;
> >@@ -103,7 +110,7 @@ static int (*_omap_save_secure_sram)(u32 *addr);
> >
> > static struct powerdomain *mpu_pwrdm, *neon_pwrdm;
> > static struct powerdomain *core_pwrdm, *per_pwrdm;
> >-static struct powerdomain *cam_pwrdm, *iva2_pwrdm, *dss_pwrdm;
> >+static struct powerdomain *cam_pwrdm, *iva2_pwrdm,
>*dss_pwrdm, *usb_pwrdm;
> >
> > static struct prm_setup_vc prm_setup = {
> > .clksetup = 0xff,
> >@@ -428,6 +435,8 @@ void omap_sram_idle(void)
> > int per_next_state = PWRDM_POWER_ON;
> > int core_next_state = PWRDM_POWER_ON;
> > int dss_state = PWRDM_POWER_ON;
> >+ int iva2_state = PWRDM_POWER_ON;
> >+ int usb_state = PWRDM_POWER_ON;
> > int core_prev_state, per_prev_state;
> > u32 sdrc_pwr = 0;
> > int per_state_modified = 0;
> >@@ -463,14 +472,28 @@ void omap_sram_idle(void)
> > if (pwrdm_read_pwrst(neon_pwrdm) == PWRDM_POWER_ON)
> > pwrdm_set_next_pwrst(neon_pwrdm, mpu_next_state);
> >
> >+ /* Get powerdomain state data */
> >+ core_next_state = pwrdm_read_next_pwrst(core_pwrdm);
> >+ dss_state = pwrdm_read_pwrst(dss_pwrdm);
> >+ iva2_state = pwrdm_read_pwrst(iva2_pwrdm);
> >+ usb_state = pwrdm_read_pwrst(usb_pwrdm);
> >+ per_next_state = pwrdm_read_next_pwrst(per_pwrdm);
> >+
> >+ /* Check if PER domain can enter OFF or not */
> >+ if (per_next_state == PWRDM_POWER_OFF) {
> >+ if ((cm_read_mod_reg(OMAP3430_PER_MOD, CM_IDLEST) &
> >+ PER_IDLEST_ALL) != PER_IDLEST_ALL) {
> >+ per_next_state = PWRDM_POWER_RET;
> >+ pwrdm_set_next_pwrst(per_pwrdm, per_next_state);
> >+ per_state_modified = 1;
> >+ }
> >+ }
> > /*
> > * Check whether core will enter idle or not. This is needed
> > * because I/O pad wakeup will fail if core stays on and PER
> > * enters off. This will also prevent unnecessary core context
> > * save / restore.
> > */
> >- core_next_state = pwrdm_read_next_pwrst(core_pwrdm);
> >- dss_state = pwrdm_read_pwrst(dss_pwrdm);
> > if (core_next_state < PWRDM_POWER_ON) {
> > core_saved_state = core_next_state;
> > if ((cm_read_mod_reg(CORE_MOD, CM_IDLEST1) &
>CORE_IDLEST1_ALL)
> >@@ -482,14 +505,16 @@ void omap_sram_idle(void)
> > core_next_state = PWRDM_POWER_ON;
> > pwrdm_set_next_pwrst(core_pwrdm,
>PWRDM_POWER_ON);
> > } else if (core_next_state == PWRDM_POWER_OFF &&
> >- dss_state == PWRDM_POWER_ON) {
> >+ (dss_state == PWRDM_POWER_ON ||
> >+ iva2_state >= PWRDM_POWER_RET ||
> >+ usb_state >= PWRDM_POWER_RET ||
> >+ per_next_state >= PWRDM_POWER_RET)) {
> > core_next_state = PWRDM_POWER_RET;
> > pwrdm_set_next_pwrst(core_pwrdm,
>PWRDM_POWER_RET);
> > }
> > }
> >
> > /* PER */
> >- per_next_state = pwrdm_read_next_pwrst(per_pwrdm);
> > if (per_next_state < PWRDM_POWER_ON) {
> > omap_uart_prepare_idle(2);
> > omap2_gpio_prepare_for_idle(per_next_state);
> >@@ -1240,6 +1265,7 @@ static int __init omap3_pm_init(void)
> > cam_pwrdm = pwrdm_lookup("cam_pwrdm");
> > iva2_pwrdm = pwrdm_lookup("iva2_pwrdm");
> > dss_pwrdm = pwrdm_lookup("dss_pwrdm");
> >+ usb_pwrdm = pwrdm_lookup("usbhost_pwrdm");
> >
> > omap_push_sram_idle();
> > #ifdef CONFIG_SUSPEND
> >--
> >1.5.4.3
> >
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