Messages in this thread | | | Date | Wed, 20 Jun 2012 09:47:24 -0700 | Subject | Re: [PATCH] PM: Prevent waiting forever on asynchronous suspend after abort | From | Mandeep Baines <> |
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On Wed, Jun 20, 2012 at 7:58 AM, Alan Stern <stern@rowland.harvard.edu> wrote: > On Tue, 19 Jun 2012, Mandeep Singh Baines wrote: > >> __device_suspend() must always send a completion. Otherwise, parent >> devices will wait forever. >> >> Commit 1e2ef05b, "PM: Limit race conditions between runtime PM and >> system sleep (v2)", introduced a regression by short-circuiting the >> complete_all() for certain error cases. >> >> This patch fixes the bug by always signalling a completion. >> >> Addresses http://crosbug.com/31972 >> >> Tested by injecting an abort via the following patch: >> >> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c >> index a004db3..e5a6fce 100644 >> --- a/drivers/usb/core/hcd-pci.c >> +++ b/drivers/usb/core/hcd-pci.c >> @@ -21,6 +21,7 @@ >> #include <linux/pci.h> >> #include <linux/usb.h> >> #include <linux/usb/hcd.h> >> +#include <linux/string.h> >> >> #include <asm/io.h> >> #include <asm/irq.h> >> @@ -477,6 +478,8 @@ static int resume_common(struct device *dev, int event) >> >> static int hcd_pci_suspend(struct device *dev) >> { >> + if (!strcmp("0000:00:1d.3", dev_name(dev))) >> + return -EBUSY; >> return suspend_common(dev, device_may_wakeup(dev)); >> } > > When you include one patch in front of another like this, doesn't it > confuse the automatic tools? You might end up getting both changes > include in the final commit. :-) >
Ah. Good point. Removed the test code and re-sent.
>> drivers/base/power/main.c | 6 ++++-- >> 1 files changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c >> index e0fb5b0..9cb845e 100644 >> --- a/drivers/base/power/main.c >> +++ b/drivers/base/power/main.c >> @@ -1031,7 +1031,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) >> dpm_wait_for_children(dev, async); >> >> if (async_error) >> - return 0; >> + goto Complete; >> >> pm_runtime_get_noresume(dev); >> if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) >> @@ -1040,7 +1040,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) >> if (pm_wakeup_pending()) { >> pm_runtime_put_sync(dev); >> async_error = -EBUSY; >> - return 0; >> + goto Complete; >> } >> >> device_lock(dev); >> @@ -1097,6 +1097,8 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) >> } >> >> device_unlock(dev); >> + >> + Complete: >> complete_all(&dev->power.completion); >> >> if (error) { > > Otherwise this looks right to me. > > Acked-by: Alan Stern <stern@rowland.harvard.edu> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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