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: 58a5e1b64b ("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>
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: bf22ff45be ("genirq: Avoid unnecessary low level irq function calls")
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>
These drivers are GPIO drivers, and the do not need to use the
legacy header in <linux/gpio.h>, go directly for
<linux/gpio/driver.h> instead.
Replace any use of GPIOF_* with 0/1, these flags are for
consumers, not drivers.
Get rid of a few gpio_to_irq() users that was littering
around the place, use local callbacks or avoid using it at
all.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Some randconfig builds fail in the mtk-eint driver:
drivers/pinctrl/mediatek/mtk-eint.c: In function 'mtk_eint_irq_handler':
drivers/pinctrl/mediatek/mtk-eint.c:324:2: error: implicit declaration of function 'chained_irq_enter'; did you mean 'rcu_irq_enter'? [-Werror=implicit-function-declaration]
chained_irq_enter(chip, desc);
^~~~~~~~~~~~~~~~~
rcu_irq_enter
drivers/pinctrl/mediatek/mtk-eint.c:367:2: error: implicit declaration of function 'chained_irq_exit'; did you mean 'rcu_irq_exit'? [-Werror=implicit-function-declaration]
The functions are declared in linux/irqchip/chained_irq.h, and including
that header makes it build in all configurations.
Fixes: e46df235b4 ("pinctrl: mediatek: refactor EINT related code for all MediaTek pinctrl can fit")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch is in preparation for adding EINT support to MT7622 pinctrl,
and the refactoring doesn't alter any existent logic.
A reason we have to refactor EINT code pieces into a generic way is that
currently, they're tightly coupled with a certain type of MediaTek pinctrl
would cause a grown in a very bad way as there is different types of
pinctrl devices getting to join.
Therefore, it is an essential or urgent thing that EINT code pieces are
refactored to eliminate any dependencies across GPIO and EINT as possible.
Additional structure mtk_eint_[xt, hw, regs] are being introduced for
indicating how maps being designed between GPIO and EINT hw number, how to
set and get GPIO state for a certain EINT pin, what characteristic on a
EINT device is present on various SoCs.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
