Thread (18 messages) 18 messages, 6 authors, 2019-06-25

Re: [PATCH 2/2] pinctrl: mediatek: Update cur_mask in mask/mask ops

From: Sean Wang <sean.wang@kernel.org>
Date: 2019-06-21 04:21:03
Also in: linux-gpio, linux-mediatek, lkml

Hi, Nicolas

On Sun, Apr 28, 2019 at 8:55 PM Nicolas Boichat [off-list ref] wrote:
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).

Instead, we just record 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 change is worth rewording the commit message you added above as an instance
and adding Fixes tag as a fixup to mean you're fixing the existing
problem in the driver.

And then Acked-by: Sean Wang [off-list ref]
quoted hunk ↗ jump to hunk
Signed-off-by: Nicolas Boichat <redacted>
---
 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 737385e86beb807..7e526bcf5e0b55c 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;
--
2.21.0.593.g511ec345e18-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help