Re: [PATCH] Watchdog: OMAP: Fix the runtime pm code to avoid module getting stuck intransition state.

[Wim Van Sebroeck <wim@xxxxxxxxx>]

Hi All,

> > On Mon, Jun 18, 2012 at 10:53 AM, Lokesh Vutla <lokeshvutla@xxxxxx> wrote:
> >> OMAP watchdong driver is adapted to runtime PM like a general device
> >> driver but it is not appropriate. It is causing couple of functional
> >> issues.
> >>
> >> 1. On OMAP4 SYSCLK can't be gated, because of issue with WDTIMER2 module,
> >> which constantly stays in "in transition" state. Value of register
> >> CM_WKUP_WDTIMER2_CLKCTRL is always 0x00010000 in this case.
> >> Issue occurs immediately after first idle, when hwmod framework tries
> >> to disable WDTIMER2 functional clock - "wd_timer2_fck". After this
> >> module falls to "in transition" state, and SYSCLK gating is blocked.
> >>
> >> 2. Due to runtime PM, watchdog timer may be completely disabled.
> >> In current code base watchdog timer is not disabled only because of
> >> issue 1. Otherwise state of WDTIMER2 module will be "Disabled", and there
> >> will be no interrupts from omap_wdt. In other words watchdog will not
> >> work at all.
> >>
> >> Watchdong is a special IP and it should not be disabled otherwise
> >> purpose of it itself is defeated. Watchdog functional clock should
> >> never be disabled. This patch updates the runtime PM handling in
> >> driver so that runtime PM is limited only during probe/shutdown
> >> and suspend/resume.
> >>
> >> The patch fixes issue 1 and 2
> >>
> >> Signed-off-by: Lokesh Vutla <lokeshvutla@xxxxxx>
> >> Acked-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> >> Cc: Wim Van Sebroeck <wim@xxxxxxxxx>
> >> ---
> 
> Any comments on this patch ? If not, can you please
> queue this up for the 3.5-rc?

Added to linux-watchdog-next.

Kind regards,
Wim.

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