[PATCH] pinctrl: single: Fix missing flush of posted write for a wakeirq

[PATCH] pinctrl: single: Fix missing flush of posted write for a wakeirq

[Tony Lindgren]

With many repeated suspend resume cycles, the pin specific wakeirq
may not always work on omaps. This is because the write to enable the
pin interrupt may not have reached the device over the interconnect
before suspend happens.

Let's fix the issue with a flush of posted write with a readback.

Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/pinctrl/pinctrl-single.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index cf9bafa..bfdf720 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -1580,6 +1580,9 @@ static inline void pcs_irq_set(struct pcs_soc_data *pcs_soc,
 		else
 			mask &= ~soc_mask;
 		pcs->write(mask, pcswi->reg);
+
+		/* flush posted write */
+		mask = pcs->read(pcswi->reg);
 		raw_spin_unlock(&pcs->lock);
 	}
 
-- 
2.8.1

Re: [PATCH] pinctrl: single: Fix missing flush of posted write for a wakeirq

[Linus Walleij]

On Tue, May 31, 2016 at 11:17 PM, Tony Lindgren <tony@atomide.com> wrote:

> With many repeated suspend resume cycles, the pin specific wakeirq
> may not always work on omaps. This is because the write to enable the
> pin interrupt may not have reached the device over the interconnect
> before suspend happens.
>
> Let's fix the issue with a flush of posted write with a readback.
>
> Reported-by: Nishanth Menon <nm@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>

Patch applied.

Is it a regression that needs to be sent to fixes and tagged
for stable?

Yours,
Linus Walleij

Re: [PATCH] pinctrl: single: Fix missing flush of posted write for a wakeirq

[Tony Lindgren]

* Linus Walleij <linus.walleij@linaro.org> [160602 05:29]:
> On Tue, May 31, 2016 at 11:17 PM, Tony Lindgren <tony@atomide.com> wrote:
> 
> > With many repeated suspend resume cycles, the pin specific wakeirq
> > may not always work on omaps. This is because the write to enable the
> > pin interrupt may not have reached the device over the interconnect
> > before suspend happens.
> >
> > Let's fix the issue with a flush of posted write with a readback.
> >
> > Reported-by: Nishanth Menon <nm@ti.com>
> > Signed-off-by: Tony Lindgren <tony@atomide.com>
> 
> Patch applied.

Thanks.

> Is it a regression that needs to be sent to fixes and tagged
> for stable?

It fixes wake from suspend in repeated cases, so at least
Android users would appreciate it in the stable trees.

Although the Android users are using vendor tree, it's still
one fix less to carry them.

So yeah, I'd vote yes for stable tag on this one.

Regards,

Tony

Re: [PATCH] pinctrl: single: Fix missing flush of posted write for a wakeirq

[Linus Walleij]

On Thu, Jun 2, 2016 at 5:19 PM, Tony Lindgren <tony@atomide.com> wrote:

> So yeah, I'd vote yes for stable tag on this one.

I trust you :)

Put in my fixes branch and tagged for stable.

Yours,
Linus Walleij