On 07/11/2013 01:16 PM, Felipe Balbi wrote:
in order to make HWMOD and pm_runtime agree on the
initial state of the device, we will unidle the device
and call pm_runtime_set_active() to tell pm_runtime
that the device is really active.
By the time driver's probe() is reached, a call to
pm_runtime_get_sync() will not cause driver's
->runtime_resume() method to be called at first, only
after a successful ->runtime_suspend().
Note that we must prevent pm_runtime transitions while
driver is probing otherwise drivers would be suspended
as soon as they call pm_runtime_use_autosuspend(). By
calling pm_runtime_forbid() before probe() and
pm_runtime_allow() after probe() we 'fix' that detail.
Note that this patch was inspired by PCI's pci_pm_init().
NAK. This is a hack.
In addition to what I've mentioned in
http://www.spinics.net/lists/arm-kernel/msg258061.html there are
following issues:
1) this patch disables call to PM runtime callbacks for all
OMAP drivers which is wrong - I've found, for example, that
omap-usb-host.c driver enables TLL in some configurations in its
.runtime_resume():
usbhs_runtime_resume()
|-omap_tll_enable()
2) even with this fix the restore context issue will not be fixed for
*non* console UARTs. Just try:
#echo 0xDEAD > dev/ttyO3 // checked on OMAP4 SDP
3) I've checked most of OMAP drivers and all of them solve such kind of
problem internally (SPI, MMC, I2C, etc.)
4) See inline
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
boot tested on top of today's Linus master
6d128e1e72bf082542e85f72e6b7ddd704193588 with OMAP4
panda. Reached console prompt and, after setting a
proper autosuspend delay, consoles autosuspend just
fine.
It needs to be tested on other platforms.
ps: note that we also call pm_runtime_set_suspended(dev)
from our late_initcall() to disable devices so that pm_runtime
and HWMOD continue to aggree on device's state.
arch/arm/mach-omap2/omap_device.c | 44 +++++++++++++++++++++++++++++++++++----
1 file changed, 40 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index 5cc9287..cb1fc1d 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -178,6 +178,26 @@ odbfd_exit:
return ret;
}
+static void omap_device_pm_init(struct platform_device *pdev)
+{
+ omap_device_enable(pdev);
+ pm_runtime_forbid(&pdev->dev);
It's wrong to use pm_runtime_forbid() - pm_runtime_get_noresume() should
be used instead.
pm_runtime_forbid()
|-rpm_resume()
+ pm_runtime_set_active(&pdev->dev);
+ device_enable_async_suspend(&pdev->dev);
why did you use device_enable_async_suspend() - it would enable async
suspend for devices - this is not related to the current issue and topic
for discussion (currently is used by usb/scsi/pci/ata drivers only).
+}
+
+static void omap_device_pm_allow(struct platform_device *pdev)
+{
+ pm_runtime_allow(&pdev->dev);
+}
+
+static void omap_device_pm_exit(struct platform_device *pdev)
+{
+ device_disable_async_suspend(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ omap_device_idle(pdev);
+}
+
static int _omap_device_notifier_call(struct notifier_block *nb,
unsigned long event, void *dev)
{
@@ -189,16 +209,31 @@ static int _omap_device_notifier_call(struct notifier_block *nb,
if (pdev->archdata.od)
omap_device_delete(pdev->archdata.od);
break;
+ case BUS_NOTIFY_BIND_DRIVER:
+ if (pdev->archdata.od)
+ omap_device_pm_init(pdev);
+ break;
+ case BUS_NOTIFY_BOUND_DRIVER:
+ if (pdev->archdata.od)
+ omap_device_pm_allow(pdev);
+ break;
+ case BUS_NOTIFY_UNBOUND_DRIVER:
+ if (pdev->archdata.od)
+ omap_device_pm_exit(pdev);
+ break;
case BUS_NOTIFY_ADD_DEVICE:
if (pdev->dev.of_node)
omap_device_build_from_dt(pdev);
- /* fall through */
+ break;
default:
- od = to_omap_device(pdev);
- if (od)
- od->_driver_status = event;
+ /* nothing */
+ break;
}
+ od = to_omap_device(pdev);
+ if (od)
+ od->_driver_status = event;
+
return NOTIFY_DONE;
}
@@ -855,6 +890,7 @@ static int __init omap_device_late_idle(struct device *dev, void *data)
dev_warn(dev, "%s: enabled but no driver. Idling\n",
__func__);
omap_device_idle(pdev);
+ pm_runtime_set_suspended(dev);
}
}
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