From: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
[ Upstream commit 9d957a959bc8c3dfe37572ac8e99affb5a885965 ]
During suspend/resume, mtk_eint_mask may be called while
wake_mask is active. For example, this happens if a wake-source
with an active interrupt handler wakes the system:
irq/pm.c:irq_pm_check_wakeup would disable the interrupt, so
that it can be handled later on in the resume flow.
However, this may happen before mtk_eint_do_resume is called:
in this case, wake_mask is loaded, and cur_mask is restored
from an older copy, re-enabling the interrupt, and causing
an interrupt storm (especially for level interrupts).
Step by step, for a line that has both wake and interrupt enabled:
1. cur_mask[irq] = 1; wake_mask[irq] = 1; EINT_EN[irq] = 1 (interrupt
enabled at hardware level)
2. System suspends, resumes due to that line (at this stage EINT_EN
== wake_mask)
3. irq_pm_check_wakeup is called, and disables the interrupt =>
EINT_EN[irq] = 0, but we still have cur_mask[irq] = 1
4. mtk_eint_do_resume is called, and restores EINT_EN = cur_mask, so
it reenables EINT_EN[irq] = 1 => interrupt storm as the driver
is not yet ready to handle the interrupt.
This patch fixes the issue in step 3, by recording all mask/unmask
changes in cur_mask. This also avoids the need to read the current
mask in eint_do_suspend, and we can remove mtk_eint_chip_read_mask
function.
The interrupt will be re-enabled properly later on, sometimes after
mtk_eint_do_resume, when the driver is ready to handle it.
Fixes: 58a5e1b64bb0 ("pinctrl: mediatek: Implement wake handler and suspend resume")
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 | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)
diff --git a/drivers/pinctrl/mediatek/mtk-eint.c b/drivers/pinctrl/mediatek/mtk-eint.c
index b9f3c02ba59d..564cfaee129d 100644
--- a/drivers/pinctrl/mediatek/mtk-eint.c
+++ b/drivers/pinctrl/mediatek/mtk-eint.c
@@ -113,6 +113,8 @@ static void mtk_eint_mask(struct irq_data *d)
void __iomem *reg = mtk_eint_get_offset(eint, d->hwirq,
eint->regs->mask_set);
+ eint->cur_mask[d->hwirq >> 5] &= ~mask;
+
writel(mask, reg);
}
@@ -123,6 +125,8 @@ static void mtk_eint_unmask(struct irq_data *d)
void __iomem *reg = mtk_eint_get_offset(eint, d->hwirq,
eint->regs->mask_clr);
+ eint->cur_mask[d->hwirq >> 5] |= mask;
+
writel(mask, reg);
if (eint->dual_edge[d->hwirq])
@@ -217,19 +221,6 @@ static void mtk_eint_chip_write_mask(const struct mtk_eint *eint,
}
}
-static void mtk_eint_chip_read_mask(const struct mtk_eint *eint,
- void __iomem *base, u32 *buf)
-{
- int port;
- void __iomem *reg;
-
- for (port = 0; port < eint->hw->ports; port++) {
- reg = base + eint->regs->mask + (port << 2);
- buf[port] = ~readl_relaxed(reg);
- /* Mask is 0 when irq is enabled, and 1 when disabled. */
- }
-}
-
static int mtk_eint_irq_request_resources(struct irq_data *d)
{
struct mtk_eint *eint = irq_data_get_irq_chip_data(d);
@@ -384,7 +375,6 @@ static void mtk_eint_irq_handler(struct irq_desc *desc)
int mtk_eint_do_suspend(struct mtk_eint *eint)
{
- mtk_eint_chip_read_mask(eint, eint->base, eint->cur_mask);
mtk_eint_chip_write_mask(eint, eint->base, eint->wake_mask);
return 0;
--
2.20.1
