Re: [RFC PATCH 1/3] PCI: rockchip: Add support for pcie wake irq
From: jeffy
Date: Thu Aug 17 2017 - 08:03:52 EST
Hi Brian,
i've tried dev_pm_set_dedicated_wake_irq, it doesn't work well on
upstream kernel(for level irq).
it looks like we would delay real set trigger type to request irq after
this commit:
1e2a7d78499e irqdomain: Don't set type when mapping an IRQ
so calling irq_set_status_flags before request irq would lose trigger
type setting.
things work well after reverted that commit, so i will send my patch
soon, and ask irq people about it :)
On 08/17/2017 01:49 AM, Brian Norris wrote:
Hi,
On Wed, Aug 16, 2017 at 03:52:22PM +0800, Jeffy Chen wrote:
Add support for PCIE_WAKE pin in rockchip pcie driver.
Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
---
drivers/pci/host/pcie-rockchip.c | 58 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index 7bb9870f6d8c..f969a6d3cd85 100644
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -38,6 +38,7 @@
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/regmap.h>
+#include <linux/suspend.h>
/*
* The upper 16 bits of PCIE_CLIENT_CONFIG are a write mask for the lower 16
@@ -226,6 +227,8 @@ struct rockchip_pcie {
struct regulator *vpcie1v8; /* 1.8V power supply */
struct regulator *vpcie0v9; /* 0.9V power supply */
struct gpio_desc *ep_gpio;
+ int wake_irq;
+ bool wake_by_pcie;
u32 lanes;
u8 root_bus_nr;
int link_gen;
@@ -853,6 +856,20 @@ static void rockchip_pcie_legacy_int_handler(struct irq_desc *desc)
chained_irq_exit(chip, desc);
}
+static irqreturn_t rockchip_pcie_wake_irq_handler(int irq, void *arg)
+{
+ struct rockchip_pcie *rockchip = arg;
+
+ rockchip->wake_by_pcie = true;
+
+ disable_irq_nosync(rockchip->wake_irq);
+ disable_irq_wake(rockchip->wake_irq);
+
+ pm_wakeup_event(rockchip->dev, 0);
+ pm_system_wakeup();
+
+ return IRQ_HANDLED;
+}
/**
* rockchip_pcie_parse_dt - Parse Device Tree
@@ -868,6 +885,7 @@ static int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
struct resource *regs;
int irq;
int err;
+ bool wakeup = 0;
'0' should be 'false'.
right
regs = platform_get_resource_byname(pdev,
IORESOURCE_MEM,
@@ -1018,6 +1036,21 @@ static int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
return err;
}
+ rockchip->wake_irq = platform_get_irq_byname(pdev, "wake");
+ if (rockchip->wake_irq >= 0) {
+ err = devm_request_irq(dev, rockchip->wake_irq,
+ rockchip_pcie_wake_irq_handler,
+ 0, "pcie-wake", rockchip);
+ if (err) {
+ dev_err(dev, "failed to request PCIe wake IRQ\n");
+ return err;
+ }
+
+ disable_irq(rockchip->wake_irq);
If you're worried about keeping this disabled at first, you can just use
this nifty trick (since this isn't a shared interrupt) -- call this
before requesting the IRQ:
irq_set_status_flags(rockchip->wake_irq, IRQ_NOAUTOEN);
You could also consider using dev_pm_set_dedicated_wake_irq() to handle
this -- but beware, it still might not quite handle level-triggered
interrupt properly. I'm pretty sure Tony Lindgren would be happy to get
testing or patches for that though :) He already sent me something a
while back but I didn't have time to test it out.
ok, that seems very handy
+ wakeup = device_property_read_bool(dev, "wakeup-source");
+ }
+ device_init_wakeup(dev, wakeup);
Shouldn't you call 'device_init_wakeup(dev, false)' on remove()?
ok
+
rockchip->vpcie3v3 = devm_regulator_get_optional(dev, "vpcie3v3");
if (IS_ERR(rockchip->vpcie3v3)) {
if (PTR_ERR(rockchip->vpcie3v3) == -EPROBE_DEFER)
@@ -1270,6 +1303,30 @@ static int rockchip_pcie_wait_l2(struct rockchip_pcie *rockchip)
return 0;
}
+static int __maybe_unused rockchip_pcie_suspend(struct device *dev)
Why do this in suspend() instead of suspend_noirq()? You shouldn't
really need a separate method here.
Note that this should be a level-triggered interrupt which remains
asserted, so there should be no chance of "missing" it if you don't
enable it in time.
And on a related note: if you try the dedicated wake irq approach, this
will only occur just before the noirq phase anyway, since
device_wakeup_arm_wake_irqs() is called in dpm_suspend_noirq().
right
+{
+ struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
+
+ rockchip->wake_by_pcie = false;
+
+ if (device_may_wakeup(dev)) {
+ enable_irq_wake(rockchip->wake_irq);
+ enable_irq(rockchip->wake_irq);
+ }
+ return 0;
+}
+
+static int __maybe_unused rockchip_pcie_resume(struct device *dev)
+{
+ struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev) && !rockchip->wake_by_pcie) {
The use of 'wake_by_pcie' is racy; an interrupt could be in flight (but
not completed), and so it could set 'wake_by_pcie' just after you're
reading this. Then, you'll get a double-disable.
I believe the safe way to handle this would be to use an atomic
test-and-set / test-and-clear approach (either atomic_cmpxchg(), or use
a spinlock).
right, and we don't need these if using dev_pm_set_dedicated_wake_irq
+ disable_irq(rockchip->wake_irq);
+ disable_irq_wake(rockchip->wake_irq);
+ }
+ return 0;
+}
+
static int __maybe_unused rockchip_pcie_suspend_noirq(struct device *dev)
{
struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
@@ -1548,6 +1605,7 @@ static int rockchip_pcie_remove(struct platform_device *pdev)
}
static const struct dev_pm_ops rockchip_pcie_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(rockchip_pcie_suspend, rockchip_pcie_resume)
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_pcie_suspend_noirq,
rockchip_pcie_resume_noirq)
};
Brian