diff options
| author | Huang Ying <ying.huang@intel.com> | 2012-08-08 09:07:39 +0800 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2012-08-21 17:32:07 -0600 |
| commit | ea8c88f13d9fb1d6b39a05bfa07ae076ca1c6803 (patch) | |
| tree | b063ab2cc5c779bf5f9ba7d92514dbfb04d64360 /drivers/pci | |
| parent | 4f9c1397e2e80e52b17ec4e39760caa807bd15c7 (diff) | |
PCI/PM: Keep parent bridge active when probing device
This patch fixes the following bug:
http://marc.info/?l=linux-pci&m=134329923124234&w=2
The root cause of the bug is as follow.
If a device is not bound with the corresponding driver, the device
runtime PM will be disabled and the device will be put into suspended
state. So that, the bridge/PCIe port connected to it may be put into
suspended and low power state. When do probing for the device later,
because the bridge/PCIe port connected to it is in low power state,
the IO access to device may fail.
To solve the issue, the bridge/PCIe port connected to the device is
put into active state before probing.
Reported-by: Bjorn Mork <bjorn@mork.no>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci-driver.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 5270f1a9932..d6fd6b6d9d4 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) { struct drv_dev_and_id *ddi = _ddi; struct device *dev = &ddi->dev->dev; + struct device *parent = dev->parent; int rc; + /* The parent bridge must be in active state when probing */ + if (parent) + pm_runtime_get_sync(parent); /* Unbound PCI devices are always set to disabled and suspended. * During probe, the device is set to enabled and active and the * usage count is incremented. If the driver supports runtime PM, @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) pm_runtime_set_suspended(dev); pm_runtime_put_noidle(dev); } + if (parent) + pm_runtime_put(parent); return rc; } |