<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/pci, branch v3.4.32</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>PCI/PM: Clean up PME state when removing a device</title>
<updated>2013-02-17T18:49:26+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rjw@sisk.pl</email>
</author>
<published>2013-02-11T19:49:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=15295d7dc33491a0a015a0f48d04bbaa696b802d'/>
<id>15295d7dc33491a0a015a0f48d04bbaa696b802d</id>
<content type='text'>
commit 249bfb83cf8ba658955f0245ac3981d941f746ee upstream.

Devices are added to pci_pme_list when drivers use pci_enable_wake()
or pci_wake_from_d3(), but they aren't removed from the list unless
the driver explicitly disables wakeup.  Many drivers never disable
wakeup, so their devices remain on the list even after they are
removed, e.g., via hotplug.  A subsequent PME poll will oops when
it tries to touch the device.

This patch disables PME# on a device before removing it, which removes
the device from pci_pme_list.  This is safe even if the device never
had PME# enabled.

This oops can be triggered by unplugging a Thunderbolt ethernet adapter
on a Macbook Pro, as reported by Daniel below.

[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2svG21yiM1wkH4_2pen2n+cr2-Zv7TbH3Gj+8MwevZjDbw@mail.gmail.com
Reported-and-tested-by: Daniel J Blueman &lt;daniel@quora.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 249bfb83cf8ba658955f0245ac3981d941f746ee upstream.

Devices are added to pci_pme_list when drivers use pci_enable_wake()
or pci_wake_from_d3(), but they aren't removed from the list unless
the driver explicitly disables wakeup.  Many drivers never disable
wakeup, so their devices remain on the list even after they are
removed, e.g., via hotplug.  A subsequent PME poll will oops when
it tries to touch the device.

This patch disables PME# on a device before removing it, which removes
the device from pci_pme_list.  This is safe even if the device never
had PME# enabled.

This oops can be triggered by unplugging a Thunderbolt ethernet adapter
on a Macbook Pro, as reported by Daniel below.

[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2svG21yiM1wkH4_2pen2n+cr2-Zv7TbH3Gj+8MwevZjDbw@mail.gmail.com
Reported-and-tested-by: Daniel J Blueman &lt;daniel@quora.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: shpchp: Handle push button event asynchronously</title>
<updated>2013-01-28T04:47:43+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2013-01-11T19:07:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1dbcda3ab27031e2b744b1f8ba48370304340519'/>
<id>1dbcda3ab27031e2b744b1f8ba48370304340519</id>
<content type='text'>
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
&lt;wangyijing@huawei.com&gt; 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 &lt;bhelgaas@google.com&gt;
CC: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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
&lt;wangyijing@huawei.com&gt; 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 &lt;bhelgaas@google.com&gt;
CC: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: pciehp: Use per-slot workqueues to avoid deadlock</title>
<updated>2013-01-28T04:47:43+00:00</updated>
<author>
<name>Yijing Wang</name>
<email>wangyijing@huawei.com</email>
</author>
<published>2013-01-11T02:15:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5f3e5a32d083008c1ad850375d24fc85a27803e4'/>
<id>5f3e5a32d083008c1ad850375d24fc85a27803e4</id>
<content type='text'>
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 &lt;daniel@quora.org&gt;
Reviewed-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Yijing Wang &lt;wangyijing@huawei.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;daniel@quora.org&gt;
Reviewed-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Yijing Wang &lt;wangyijing@huawei.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Allow pcie_aspm=force even when FADT indicates it is unsupported</title>
<updated>2013-01-28T04:47:43+00:00</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2012-11-27T14:09:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=11cfb2b163f483a4c97e5a229635d0f6b23bd5ac'/>
<id>11cfb2b163f483a4c97e5a229635d0f6b23bd5ac</id>
<content type='text'>
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 &lt;colin.king@canonical.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;colin.king@canonical.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI/AER: pci_get_domain_bus_and_slot() call missing required pci_dev_put()</title>
<updated>2013-01-28T04:47:43+00:00</updated>
<author>
<name>Betty Dall</name>
<email>betty.dall@hp.com</email>
</author>
<published>2013-01-13T22:46:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7145808ebc1f0188cf9decbfd23279b0c10022f1'/>
<id>7145808ebc1f0188cf9decbfd23279b0c10022f1</id>
<content type='text'>
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 &lt;betty.dall@hp.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Shuah Khan &lt;shuah.khan@hp.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;betty.dall@hp.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Shuah Khan &lt;shuah.khan@hp.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Reduce Ricoh 0xe822 SD card reader base clock frequency to 50MHz</title>
<updated>2013-01-11T17:07:16+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@amacapital.net</email>
</author>
<published>2012-12-01T20:37:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7164ac211086207dc371e3b32165226e28e2dcfa'/>
<id>7164ac211086207dc371e3b32165226e28e2dcfa</id>
<content type='text'>
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 &lt;luto@amacapital.net&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Chris Ball &lt;cjb@laptop.org&gt;
CC: Manoj Iyer &lt;manoj.iyer@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;luto@amacapital.net&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Chris Ball &lt;cjb@laptop.org&gt;
CC: Manoj Iyer &lt;manoj.iyer@canonical.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Check P2P bridge for invalid secondary/subordinate range</title>
<updated>2012-10-12T20:38:48+00:00</updated>
<author>
<name>Yinghai Lu</name>
<email>yinghai@kernel.org</email>
</author>
<published>2012-09-11T00:19:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b790ef23cd1fd3fece4777e90d85a945c4820ae7'/>
<id>b790ef23cd1fd3fece4777e90d85a945c4820ae7</id>
<content type='text'>
commit 1965f66e7db08d1ebccd24a59043eba826cc1ce8 upstream.

For bridges with "secondary &gt; subordinate", i.e., invalid bus number
apertures, we don't enumerate anything behind the bridge unless the
user specified "pci=assign-busses".

This patch makes us automatically try to reassign the downstream bus
numbers in this case (just for that bridge, not for all bridges as
"pci=assign-busses" does).

We don't discover all the devices on the Intel DP43BF motherboard
without this change (or "pci=assign-busses") because its BIOS configures
a bridge as:

    pci 0000:00:1e.0: PCI bridge to [bus 20-08] (subtractive decode)

[bhelgaas: changelog, change message to dev_info]
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=18412
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=625754
Reported-by: Brian C. Huffman &lt;bhuffman@graze.net&gt;
Reported-by: VL &lt;vl.homutov@gmail.com&gt;
Tested-by: VL &lt;vl.homutov@gmail.com&gt;
Signed-off-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1965f66e7db08d1ebccd24a59043eba826cc1ce8 upstream.

For bridges with "secondary &gt; subordinate", i.e., invalid bus number
apertures, we don't enumerate anything behind the bridge unless the
user specified "pci=assign-busses".

This patch makes us automatically try to reassign the downstream bus
numbers in this case (just for that bridge, not for all bridges as
"pci=assign-busses" does).

We don't discover all the devices on the Intel DP43BF motherboard
without this change (or "pci=assign-busses") because its BIOS configures
a bridge as:

    pci 0000:00:1e.0: PCI bridge to [bus 20-08] (subtractive decode)

[bhelgaas: changelog, change message to dev_info]
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=18412
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=625754
Reported-by: Brian C. Huffman &lt;bhuffman@graze.net&gt;
Reported-by: VL &lt;vl.homutov@gmail.com&gt;
Tested-by: VL &lt;vl.homutov@gmail.com&gt;
Signed-off-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: acpiphp: check whether _ADR evaluation succeeded</title>
<updated>2012-10-12T20:38:38+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2012-06-20T22:18:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=95482ba9494658e69aecf0f97b64f3f2ab82af62'/>
<id>95482ba9494658e69aecf0f97b64f3f2ab82af62</id>
<content type='text'>
commit dfb117b3e50c52c7b3416db4a4569224b8db80bb upstream.

Check whether we evaluated _ADR successfully.  Previously we ignored
failure, so we would have used garbage data from the stack as the device
and function number.

We return AE_OK so that we ignore only this slot and continue looking
for other slots.

Found by Coverity (CID 113981).

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit dfb117b3e50c52c7b3416db4a4569224b8db80bb upstream.

Check whether we evaluated _ADR successfully.  Previously we ignored
failure, so we would have used garbage data from the stack as the device
and function number.

We return AE_OK so that we ignore only this slot and continue looking
for other slots.

Found by Coverity (CID 113981).

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: EHCI: Fix crash during hibernation on ASUS computers</title>
<updated>2012-09-14T17:00:20+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rjw@sisk.pl</email>
</author>
<published>2012-08-12T21:26:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=81d030df8597288a2fd12950aaf0842dbfa0b216'/>
<id>81d030df8597288a2fd12950aaf0842dbfa0b216</id>
<content type='text'>
commit 0b68c8e2c3afaf9807eb1ebe0ccfb3b809570aa4 upstream.

Commit dbf0e4c (PCI: EHCI: fix crash during suspend on ASUS
computers) added a workaround for an ASUS suspend issue related to
USB EHCI and a bug in a number of ASUS BIOSes that attempt to shut
down the EHCI controller during system suspend if its PCI command
register doesn't contain 0 at that time.

It turns out that the same workaround is necessary in the analogous
hibernation code path, so add it.

References: https://bugzilla.kernel.org/show_bug.cgi?id=45811
Reported-and-tested-by: Oleksij Rempel &lt;bug-track@fisher-privat.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0b68c8e2c3afaf9807eb1ebe0ccfb3b809570aa4 upstream.

Commit dbf0e4c (PCI: EHCI: fix crash during suspend on ASUS
computers) added a workaround for an ASUS suspend issue related to
USB EHCI and a bug in a number of ASUS BIOSes that attempt to shut
down the EHCI controller during system suspend if its PCI command
register doesn't contain 0 at that time.

It turns out that the same workaround is necessary in the analogous
hibernation code path, so add it.

References: https://bugzilla.kernel.org/show_bug.cgi?id=45811
Reported-and-tested-by: Oleksij Rempel &lt;bug-track@fisher-privat.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: EHCI: fix crash during suspend on ASUS computers</title>
<updated>2012-07-16T16:04:39+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2012-07-09T15:09:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0659cf9dcd148f6771c056fa95976fda9c5abf9d'/>
<id>0659cf9dcd148f6771c056fa95976fda9c5abf9d</id>
<content type='text'>
commit dbf0e4c7257f8d684ec1a3c919853464293de66e upstream.

Quite a few ASUS computers experience a nasty problem, related to the
EHCI controllers, when going into system suspend.  It was observed
that the problem didn't occur if the controllers were not put into the
D3 power state before starting the suspend, and commit
151b61284776be2d6f02d48c23c3625678960b97 (USB: EHCI: fix crash during
suspend on ASUS computers) was created to do this.

It turned out this approach messed up other computers that didn't have
the problem -- it prevented USB wakeup from working.  Consequently
commit c2fb8a3fa25513de8fedb38509b1f15a5bbee47b (USB: add
NO_D3_DURING_SLEEP flag and revert 151b61284776be2) was merged; it
reverted the earlier commit and added a whitelist of known good board
names.

Now we know the actual cause of the problem.  Thanks to AceLan Kao for
tracking it down.

According to him, an engineer at ASUS explained that some of their
BIOSes contain a bug that was added in an attempt to work around a
problem in early versions of Windows.  When the computer goes into S3
suspend, the BIOS tries to verify that the EHCI controllers were first
quiesced by the OS.  Nothing's wrong with this, but the BIOS does it
by checking that the PCI COMMAND registers contain 0 without checking
the controllers' power state.  If the register isn't 0, the BIOS
assumes the controller needs to be quiesced and tries to do so.  This
involves making various MMIO accesses to the controller, which don't
work very well if the controller is already in D3.  The end result is
a system hang or memory corruption.

Since the value in the PCI COMMAND register doesn't matter once the
controller has been suspended, and since the value will be restored
anyway when the controller is resumed, we can work around the BIOS bug
simply by setting the register to 0 during system suspend.  This patch
(as1590) does so and also reverts the second commit mentioned above,
which is now unnecessary.

In theory we could do this for every PCI device.  However to avoid
introducing new problems, the patch restricts itself to EHCI host
controllers.

Finally the affected systems can suspend with USB wakeup working
properly.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=37632
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=42728
Based-on-patch-by: AceLan Kao &lt;acelan.kao@canonical.com&gt;
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Tested-by: Dâniel Fraga &lt;fragabr@gmail.com&gt;
Tested-by: Javier Marcet &lt;jmarcet@gmail.com&gt;
Tested-by: Andrey Rahmatullin &lt;wrar@wrar.name&gt;
Tested-by: Oleksij Rempel &lt;bug-track@fisher-privat.net&gt;
Tested-by: Pavel Pisa &lt;pisa@cmp.felk.cvut.cz&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit dbf0e4c7257f8d684ec1a3c919853464293de66e upstream.

Quite a few ASUS computers experience a nasty problem, related to the
EHCI controllers, when going into system suspend.  It was observed
that the problem didn't occur if the controllers were not put into the
D3 power state before starting the suspend, and commit
151b61284776be2d6f02d48c23c3625678960b97 (USB: EHCI: fix crash during
suspend on ASUS computers) was created to do this.

It turned out this approach messed up other computers that didn't have
the problem -- it prevented USB wakeup from working.  Consequently
commit c2fb8a3fa25513de8fedb38509b1f15a5bbee47b (USB: add
NO_D3_DURING_SLEEP flag and revert 151b61284776be2) was merged; it
reverted the earlier commit and added a whitelist of known good board
names.

Now we know the actual cause of the problem.  Thanks to AceLan Kao for
tracking it down.

According to him, an engineer at ASUS explained that some of their
BIOSes contain a bug that was added in an attempt to work around a
problem in early versions of Windows.  When the computer goes into S3
suspend, the BIOS tries to verify that the EHCI controllers were first
quiesced by the OS.  Nothing's wrong with this, but the BIOS does it
by checking that the PCI COMMAND registers contain 0 without checking
the controllers' power state.  If the register isn't 0, the BIOS
assumes the controller needs to be quiesced and tries to do so.  This
involves making various MMIO accesses to the controller, which don't
work very well if the controller is already in D3.  The end result is
a system hang or memory corruption.

Since the value in the PCI COMMAND register doesn't matter once the
controller has been suspended, and since the value will be restored
anyway when the controller is resumed, we can work around the BIOS bug
simply by setting the register to 0 during system suspend.  This patch
(as1590) does so and also reverts the second commit mentioned above,
which is now unnecessary.

In theory we could do this for every PCI device.  However to avoid
introducing new problems, the patch restricts itself to EHCI host
controllers.

Finally the affected systems can suspend with USB wakeup working
properly.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=37632
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=42728
Based-on-patch-by: AceLan Kao &lt;acelan.kao@canonical.com&gt;
Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Tested-by: Dâniel Fraga &lt;fragabr@gmail.com&gt;
Tested-by: Javier Marcet &lt;jmarcet@gmail.com&gt;
Tested-by: Andrey Rahmatullin &lt;wrar@wrar.name&gt;
Tested-by: Oleksij Rempel &lt;bug-track@fisher-privat.net&gt;
Tested-by: Pavel Pisa &lt;pisa@cmp.felk.cvut.cz&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
