linux-toradex.git/drivers/pci, branch v3.7.6

PCI: shpchp: Use per-slot workqueues to avoid deadlock

2013-01-28T04:49:01+00:00

commit f652e7d2916fe2fcf9e7d709aa5b7476b431e2dd upstream.

When we have an SHPC-capable bridge with a second SHPC-capable bridge
below it, pushing the upstream bridge's attention button causes a
deadlock.

The deadlock happens because we use the shpchp_wq workqueue to run
shpchp_pushbutton_thread(), which uses shpchp_disable_slot() to remove
devices below the upstream bridge.  When we remove the downstream bridge,
we call shpc_remove(), the shpchp driver's .remove() method.  That calls
flush_workqueue(shpchp_wq), which deadlocks because the
shpchp_pushbutton_thread() work item is still running.

This patch avoids the deadlock by creating a workqueue for every slot
and removing the single shared workqueue.

Here's the call path that leads to the deadlock:

  shpchp_queue_pushbutton_work
    queue_work(shpchp_wq)		# shpchp_pushbutton_thread
    ...

  shpchp_pushbutton_thread
    shpchp_disable_slot
      remove_board
        shpchp_unconfigure_device
          pci_stop_and_remove_bus_device
            ...
              shpc_remove		# shpchp driver .remove method
                hpc_release_ctlr
                  cleanup_slots
                    flush_workqueue(shpchp_wq)

This change is based on code inspection, since we don't have hardware
with this topology.

Based-on-patch-by: Yijing Wang 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

PCI: shpchp: Handle push button event asynchronously

2013-01-28T04:49:01+00:00

commit d347e75847c1fb299c97736638f45e6ea39702d4 upstream.

Use non-ordered workqueue for attention button events.

Attention button events on each slot can be handled asynchronously. So
we should use non-ordered workqueue. This patch also removes ordered
workqueue in shpchp as a result.

486b10b9f4 ("PCI: pciehp: Handle push button event asynchronously") made
the same change to pciehp.  I split this out from a patch by Yijing Wang
 so we fix one thing at a time and to make the
shpchp history correspond more closely with the pciehp history.

Signed-off-by: Bjorn Helgaas 
CC: Kenji Kaneshige 
Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Use per-slot workqueues to avoid deadlock

2013-01-28T04:49:01+00:00

commit c2be6f93b383c873a4f9d521afa49b1b67d06085 upstream.

When we have a hotplug-capable PCIe port with a second hotplug-capable
PCIe port below it, removing the device below the upstream port causes
a deadlock.

The deadlock happens because we use the pciehp_wq workqueue to run
pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices
below the upstream port. When we remove the downstream PCIe port, we call
pciehp_remove(), the pciehp driver's .remove() method. That calls
flush_workqueue(pciehp_wq), which deadlocks because the
pciehp_power_thread() work item is still running.

This patch avoids the deadlock by creating a workqueue for every PCIe port
and removing the single shared workqueue.

Here's the call path that leads to the deadlock:

pciehp_queue_pushbutton_work
queue_work(pciehp_wq) # queue pciehp_power_thread
...

pciehp_power_thread
pciehp_disable_slot
remove_board
pciehp_unconfigure_device
pci_stop_and_remove_bus_device
...
pciehp_remove # pciehp driver .remove method
pciehp_release_ctrl
pcie_cleanup_slot
flush_workqueue(pciehp_wq)

This is fairly urgent because it can be caused by simply unplugging a
Thunderbolt adapter, as reported by Daniel below.

[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com
Reported-and-tested-by: Daniel J Blueman
Reviewed-by: Kenji Kaneshige
Signed-off-by: Yijing Wang
Signed-off-by: Bjorn Helgaas
Signed-off-by: Greg Kroah-Hartman

PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported

2013-01-28T04:49:01+00:00

commit 9e16721498b0c3d3ebfa0b503c63d35c0a4c0642 upstream.

Right now using pcie_aspm=force will not enable ASPM if the FADT indicates
ASPM is unsupported.  However, the semantics of force should probably allow
for this, especially as they did before 3c076351c4 ("PCI: Rework ASPM
disable code")

This patch just skips the clearing of any ASPM setup that the firmware has
carried out on this bus if pcie_aspm=force is being used.

Reference: http://bugs.launchpad.net/bugs/962038
Signed-off-by: Colin Ian King 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

PCI/AER: pci_get_domain_bus_and_slot() call missing required pci_dev_put()

2013-01-28T04:49:01+00:00

commit a82b6af37d20bfe6e99a4d890f1cf1d89059929f upstream.

The function aer_recover_queue() calls pci_get_domain_bus_and_slot(), which
requires that the caller decrement the reference count with pci_dev_put().
This patch adds the missing call to pci_dev_put().

Signed-off-by: Betty Dall 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Shuah Khan 
Signed-off-by: Greg Kroah-Hartman

PCI/PM: Do not suspend port if any subordinate device needs PME polling

2013-01-11T17:19:03+00:00

commit c733b77475707cc3980542c86ee0ad5c841d544c upstream.

Ulrich reported that his USB3 cardreader does not work reliably when
connected to the USB3 port.  It turns out that USB3 controller failed to
awaken when plugging in the USB3 cardreader.  Further experiments found
that the USB3 host controller can only be awakened via polling, not via PME
interrupt.  But if the PCIe port to which the USB3 host controller is
connected is suspended, we cannot poll the controller because its config
space is not accessible when the PCIe port is in a low power state.

To solve the issue, the PCIe port will not be suspended if any subordinate
device needs PME polling.

[bhelgaas: use bool consistently rather than mixing int/bool]
Reference: http://lkml.kernel.org/r/50841CCC.9030809@uli-eckhardt.de
Reported-by: Ulrich Eckhardt 
Tested-by: Sarah Sharp 
Signed-off-by: Huang Ying 
Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PCI: Reduce Ricoh 0xe822 SD card reader base clock frequency to 50MHz

2013-01-11T17:19:02+00:00

commit 812089e01b9f65f90fc8fc670d8cce72a0e01fbb upstream.

Otherwise it fails like this on cards like the Transcend 16GB SDHC card:

    mmc0: new SDHC card at address b368
    mmcblk0: mmc0:b368 SDC   15.0 GiB
    mmcblk0: error -110 sending status command, retrying
    mmcblk0: error -84 transferring data, sector 0, nr 8, cmd response 0x900, card status 0xb0

Tested on my Lenovo x200 laptop.

[bhelgaas: changelog]
Signed-off-by: Andy Lutomirski 
Signed-off-by: Bjorn Helgaas 
Acked-by: Chris Ball 
CC: Manoj Iyer 
Signed-off-by: Greg Kroah-Hartman

PCI/PM: Keep runtime PM enabled for unbound PCI devices

2013-01-11T17:19:02+00:00

commit 967577b062417b4e4b8e27b711220f4124f5153a upstream.

For unbound PCI devices, what we need is:

 - Always in D0 state, because some devices do not work again after
   being put into D3 by the PCI bus.

 - In SUSPENDED state if allowed, so that the parent devices can still
   be put into low power state.

To satisfy these requirements, the runtime PM for the unbound PCI
devices are disabled and set to SUSPENDED state.  One issue of this
solution is that the PCI devices will be put into SUSPENDED state even
if the SUSPENDED state is forbidden via the sysfs interface
(.../power/control) of the device.  This is not an issue for most
devices, because most PCI devices are not used at all if unbound.
But there are exceptions.  For example, unbound VGA card can be used
for display, but suspending its parents makes it stop working.

To fix the issue, we keep the runtime PM enabled when the PCI devices
are unbound.  But the runtime PM callbacks will do nothing if the PCI
devices are unbound.  This way, we can put the PCI devices into
SUSPENDED state without putting the PCI devices into D3 state.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=48201
Signed-off-by: Huang Ying 
Signed-off-by: Bjorn Helgaas 
Acked-by: Alan Stern 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PCI/portdrv: Don't create hotplug slots unless port supports hotplug

2012-11-05T23:59:59+00:00

Commit 2dcfaf85 mistakenly dropped the "flags & PCI_EXP_FLAGS_SLOT" test,
so now we create hotplug slots even for PCIe port devices that don't
support hotplug.  This patch fixes this problem.

[bhelgaas: changelog]
Signed-off-by: Taku Izumi 
Signed-off-by: Bjorn Helgaas 
Acked-by: Yinghai Lu 
Reviewed-by: Jiang Liu

PCI/PM: Fix proc config reg access for D3cold and bridge suspending

2012-11-05T17:46:23+00:00

In https://bugzilla.kernel.org/show_bug.cgi?id=48981
Peter reported that /proc/bus/pci/??/??.? does not work for 3.6.
This is because the device configuration space registers are
not accessible if the corresponding parent bridge is suspended or
the device is put into D3cold state.

This is the same as /sys/bus/pci/devices/0000:??:??.?/config access
issue.  So the function used to solve sysfs issue is used to solve
this issue.

This patch moves pci_config_pm_runtime_get()/_put() from pci/pci-sysfs.c
to pci/pci.c and makes them extern so they can be used by both the
sysfs and proc paths.

[bhelgaas: changelog, references, reporters]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=48981
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=49031
Reported-by: Forrest Loomis 
Reported-by: Peter 
Reported-by: Micael Dias 
Signed-off-by: Huang Ying 
Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki 
CC: stable@vger.kernel.org		# v3.6+