Re: [PATCH] OMAP3: USBHOST: Fix prcm interrupt handler

[Kevin Hilman <khilman@deeprootsystems.com>]

Vikram Pandita <vikram.pandita@ti.com> writes:

> For clearing the PM_WKST of USBHOST domain, two fclocks need
> to be enabled: HOST1 and HOST2
>
> Current code just enables HOST1 fclock and thus not clearing the
> Wake status of usbhost domain correctly

I think the changelog needs a little more detail.  Something like:

USBHOST module has 2 fclocks (for HOST1 and HOST2), only one iclock
and only a single bit in the WKST register to indicate a wakeup event.

Because of the single WKST bit, we cannot know whether a wakeup event
was on HOST1 or HOST2, so enable both fclocks before clearing the
wakeup event to ensure both hosts can properly clear the event.

And shortlog (subject) should be:

OMAP3: PM: USBHOST: clear wakeup events on both hosts

> Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
> ---
>  arch/arm/mach-omap2/pm34xx.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index e80d59f..4cbeff1 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -264,8 +264,10 @@ static irqreturn_t prcm_interrupt_handler (int irq, void *dev_id)
>  					       CM_FCLKEN);
>  			cm_set_mod_reg_bits(wkst, OMAP3430ES2_USBHOST_MOD,
>  					    CM_ICLKEN);
> -			cm_set_mod_reg_bits(wkst, OMAP3430ES2_USBHOST_MOD,
> -					    CM_FCLKEN);
> +			cm_set_mod_reg_bits((1<<OMAP3430ES2_EN_USBHOST2_SHIFT)|
> +					(1<<OMAP3430ES2_EN_USBHOST1_SHIFT),
> +					OMAP3430ES2_USBHOST_MOD,
> +					CM_FCLKEN);

Instead how about keeping original code, but just add something like:

        /* We don't know whether HOST1 or HOST2 woke us up, so
         * enable both clocks. */
        clken = wkst | (1 << OMAP3430ES2_EN_USBHOST2_SHIFT);

Then write 'clken' to the FCLKEN reg and original 'wkst' to the WKST
reg...

>  			prm_write_mod_reg(wkst, OMAP3430ES2_USBHOST_MOD,
>  					  PM_WKST);

otherwise you're writing undefined bits here.

Kevin