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

commit 0ac3c0a4025f41748a083bdd4970cb3ede802b15 upstream.

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>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index 23b6b8c29a99eb9a65b7c2bd11e02da7356afc97..73d8d47ea465a93902fb5702fbf84d6f7afaca5e 100644 (file)
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -1576,6 +1576,9 @@ 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);
        }