[PATCH AUTOSEL 5.1 33/39] pinctrl: mediatek: Ignore interrupts that are wake only during resume

From: Sasha Levin
Date: Tue Jul 02 2019 - 22:16:14 EST


From: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>

[ Upstream commit 35594bc7cecf3a78504b590e350570e8f4d7779e ]

Before suspending, mtk-eint would set the interrupt mask to the
one in wake_mask. However, some of these interrupts may not have a
corresponding interrupt handler, or the interrupt may be disabled.

On resume, the eint irq handler would trigger nevertheless,
and irq/pm.c:irq_pm_check_wakeup would be called, which would
try to call irq_disable. However, if the interrupt is not enabled
(irqd_irq_disabled(&desc->irq_data) is true), the call does nothing,
and the interrupt is left enabled in the eint driver.

Especially for level-sensitive interrupts, this will lead to an
interrupt storm on resume.

If we detect that an interrupt is only in wake_mask, but not in
cur_mask, we can just mask it out immediately (as mtk_eint_resume
would do anyway at a later stage in the resume sequence, when
restoring cur_mask).

Fixes: bf22ff45bed6 ("genirq: Avoid unnecessary low level irq function calls")
Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
Acked-by: Sean Wang <sean.wang@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/pinctrl/mediatek/mtk-eint.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/mediatek/mtk-eint.c b/drivers/pinctrl/mediatek/mtk-eint.c
index f464f8cd274b..737385e86beb 100644
--- a/drivers/pinctrl/mediatek/mtk-eint.c
+++ b/drivers/pinctrl/mediatek/mtk-eint.c
@@ -318,7 +318,7 @@ static void mtk_eint_irq_handler(struct irq_desc *desc)
struct irq_chip *chip = irq_desc_get_chip(desc);
struct mtk_eint *eint = irq_desc_get_handler_data(desc);
unsigned int status, eint_num;
- int offset, index, virq;
+ int offset, mask_offset, index, virq;
void __iomem *reg = mtk_eint_get_offset(eint, 0, eint->regs->stat);
int dual_edge, start_level, curr_level;

@@ -328,10 +328,24 @@ static void mtk_eint_irq_handler(struct irq_desc *desc)
status = readl(reg);
while (status) {
offset = __ffs(status);
+ mask_offset = eint_num >> 5;
index = eint_num + offset;
virq = irq_find_mapping(eint->domain, index);
status &= ~BIT(offset);

+ /*
+ * If we get an interrupt on pin that was only required
+ * for wake (but no real interrupt requested), mask the
+ * interrupt (as would mtk_eint_resume do anyway later
+ * in the resume sequence).
+ */
+ if (eint->wake_mask[mask_offset] & BIT(offset) &&
+ !(eint->cur_mask[mask_offset] & BIT(offset))) {
+ writel_relaxed(BIT(offset), reg -
+ eint->regs->stat +
+ eint->regs->mask_set);
+ }
+
dual_edge = eint->dual_edge[index];
if (dual_edge) {
/*
--
2.20.1