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authorNicolas Boichat <drinkcat@chromium.org>2019-06-26 06:54:45 +0300
committerLinus Walleij <linus.walleij@linaro.org>2019-06-27 14:22:11 +0300
commit9d957a959bc8c3dfe37572ac8e99affb5a885965 (patch)
tree77e99fc0c0e3d7a3d9ed7b73a97f2dcd49d0938f /drivers
parent35594bc7cecf3a78504b590e350570e8f4d7779e (diff)
downloadlinux-9d957a959bc8c3dfe37572ac8e99affb5a885965.tar.xz
pinctrl: mediatek: Update cur_mask in mask/mask ops
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@chromium.org> Acked-by: Sean Wang <sean.wang@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pinctrl/mediatek/mtk-eint.c18
1 files changed, 4 insertions, 14 deletions
diff --git a/drivers/pinctrl/mediatek/mtk-eint.c b/drivers/pinctrl/mediatek/mtk-eint.c
index 737385e86beb..7e526bcf5e0b 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;