> -----Original Message-----
> From: ext Paul Walmsley [mailto:[email protected]]
> Sent: 9. maaliskuuta 2011 1:02
> To: Jokiniemi Kalle (Nokia-MS/Tampere)
> Cc: Kevin Hilman; [email protected]; [email protected]; b-
> [email protected]; Koskinen Ilkka (Nokia-MS/Tampere); Charulatha
> Varadarajan; [email protected]
> Subject: Re: [PATCH 0/2] omap_wdt: fix interface clock handling
>
> Hi,
>
> On Tue, 8 Mar 2011, Kevin Hilman wrote:
>
> > Kalle Jokiniemi <[email protected]> writes:
> >
> > > The runtime PM does not offer enough granularity to control
> > > individual clocks separately as needed. Current pm implementation of
> > > omap_wdt blocks the CORE power domain from idling in OMAP SoC, as it
> > > keeps the interface clock of the watchdog always on. This causes
> > > severe power leakage in devices where the omap watchdog is in active
> > > use.
> >
> > The iclk remains active because it's in hardware-controlled auto-idle
> > mode.
>
> ... and we think that the interface clock never enters auto-idle because the
> WDT doesn't SIdleAck to the PRCM until the special sequence has been
> written to the WDT registers to disable it. So even if its *CLKEN bits are
> set to
> zero, the WDT prevents the system from going idle.
>
> > I believe if you set the WDT hwmod to software-supported idle
> > (OCPIF_SWSUP_IDLE), the runtime PM idle (which calls omap_device idle,
> > then omap_hwmod_idle) should also gate the interface clock.
>
> Agreed.
>
> Kalle, since you requested patches, here's one that implements Kevin's first
> suggestion. I will reply to your second patch with its equivalent for PM
> runtime. The patches have been compile-tested only. Perhaps you could
> see if they solve your problem?
Thanks Paul, I'll try these out.
- Kalle
>
>
> regards,
>
> - Paul
>
> ---
> arch/arm/mach-omap2/omap_hwmod_2420_data.c | 1 +
> arch/arm/mach-omap2/omap_hwmod_2430_data.c | 1 +
> arch/arm/mach-omap2/omap_hwmod_3xxx_data.c | 1 +
> arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 1 +
> 4 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod_2420_data.c
> b/arch/arm/mach-omap2/omap_hwmod_2420_data.c
> index 1611f74..df4950d 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_2420_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_2420_data.c
> @@ -974,6 +974,7 @@ static struct omap_hwmod_ocp_if
> omap2420_l4_wkup__wd_timer2 = {
> .clk = "mpu_wdt_ick",
> .addr = omap2420_wd_timer2_addrs,
> .addr_cnt = ARRAY_SIZE(omap2420_wd_timer2_addrs),
> + .flags = OCPIF_SWSUP_IDLE,
> .user = OCP_USER_MPU | OCP_USER_SDMA,
> };
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod_2430_data.c
> b/arch/arm/mach-omap2/omap_hwmod_2430_data.c
> index 809424f..21fc908 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_2430_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_2430_data.c
> @@ -1074,6 +1074,7 @@ static struct omap_hwmod_ocp_if
> omap2430_l4_wkup__wd_timer2 = {
> .clk = "mpu_wdt_ick",
> .addr = omap2430_wd_timer2_addrs,
> .addr_cnt = ARRAY_SIZE(omap2430_wd_timer2_addrs),
> + .flags = OCPIF_SWSUP_IDLE,
> .user = OCP_USER_MPU | OCP_USER_SDMA,
> };
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
> b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
> index 457df3e..7ae2dab 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
> @@ -1234,6 +1234,7 @@ static struct omap_hwmod_ocp_if
> omap3xxx_l4_wkup__wd_timer2 = {
> .clk = "wdt2_ick",
> .addr = omap3xxx_wd_timer2_addrs,
> .addr_cnt = ARRAY_SIZE(omap3xxx_wd_timer2_addrs),
> + .flags = OCPIF_SWSUP_IDLE,
> .user = OCP_USER_MPU | OCP_USER_SDMA,
> };
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> index 7b72316..2038813 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> @@ -4901,6 +4901,7 @@ static struct omap_hwmod_ocp_if
> omap44xx_l4_wkup__wd_timer2 = {
> .clk = "l4_wkup_clk_mux_ck",
> .addr = omap44xx_wd_timer2_addrs,
> .addr_cnt = ARRAY_SIZE(omap44xx_wd_timer2_addrs),
> + .flags = OCPIF_SWSUP_IDLE,
> .user = OCP_USER_MPU | OCP_USER_SDMA,
> };
>
> --
> 1.7.2.3
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