<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/pci, branch v3.4.107</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>PCI: Handle read-only BARs on AMD CS553x devices</title>
<updated>2015-04-14T09:34:04+00:00</updated>
<author>
<name>Myron Stowe</name>
<email>myron.stowe@redhat.com</email>
</author>
<published>2015-02-03T23:01:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d4e393820d2ed20fc6a4088f3eda44458764d997'/>
<id>d4e393820d2ed20fc6a4088f3eda44458764d997</id>
<content type='text'>
commit 06cf35f903aa6da0cc8d9f81e9bcd1f7e1b534bb upstream.

Some AMD CS553x devices have read-only BARs because of a firmware or
hardware defect.  There's a workaround in quirk_cs5536_vsa(), but it no
longer works after 36e8164882ca ("PCI: Restore detection of read-only
BARs").  Prior to 36e8164882ca, we filled in res-&gt;start; afterwards we
leave it zeroed out.  The quirk only updated the size, so the driver tried
to use a region starting at zero, which didn't work.

Expand quirk_cs5536_vsa() to read the base addresses from the BARs and
hard-code the sizes.

On Nix's system BAR 2's read-only value is 0x6200.  Prior to 36e8164882ca,
we interpret that as a 512-byte BAR based on the lowest-order bit set.  Per
datasheet sec 5.6.1, that BAR (MFGPT) requires only 64 bytes; use that to
avoid clearing any address bits if a platform uses only 64-byte alignment.

[bhelgaas: changelog, reduce BAR 2 size to 64]
Fixes: 36e8164882ca ("PCI: Restore detection of read-only BARs")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=85991#c4
Link: http://support.amd.com/TechDocs/31506_cs5535_databook.pdf
Link: http://support.amd.com/TechDocs/33238G_cs5536_db.pdf
Reported-and-tested-by: Nix &lt;nix@esperi.org.uk&gt;
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 06cf35f903aa6da0cc8d9f81e9bcd1f7e1b534bb upstream.

Some AMD CS553x devices have read-only BARs because of a firmware or
hardware defect.  There's a workaround in quirk_cs5536_vsa(), but it no
longer works after 36e8164882ca ("PCI: Restore detection of read-only
BARs").  Prior to 36e8164882ca, we filled in res-&gt;start; afterwards we
leave it zeroed out.  The quirk only updated the size, so the driver tried
to use a region starting at zero, which didn't work.

Expand quirk_cs5536_vsa() to read the base addresses from the BARs and
hard-code the sizes.

On Nix's system BAR 2's read-only value is 0x6200.  Prior to 36e8164882ca,
we interpret that as a 512-byte BAR based on the lowest-order bit set.  Per
datasheet sec 5.6.1, that BAR (MFGPT) requires only 64 bytes; use that to
avoid clearing any address bits if a platform uses only 64-byte alignment.

[bhelgaas: changelog, reduce BAR 2 size to 64]
Fixes: 36e8164882ca ("PCI: Restore detection of read-only BARs")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=85991#c4
Link: http://support.amd.com/TechDocs/31506_cs5535_databook.pdf
Link: http://support.amd.com/TechDocs/33238G_cs5536_db.pdf
Reported-and-tested-by: Nix &lt;nix@esperi.org.uk&gt;
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Restore detection of read-only BARs</title>
<updated>2015-04-14T09:33:42+00:00</updated>
<author>
<name>Myron Stowe</name>
<email>myron.stowe@redhat.com</email>
</author>
<published>2014-10-30T17:54:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=73837b3ae4fb51cd5d48c9230d1b0e627a50c160'/>
<id>73837b3ae4fb51cd5d48c9230d1b0e627a50c160</id>
<content type='text'>
commit 36e8164882ca6d3c41cb91e6f09a3ed236841f80 upstream.

Commit 6ac665c63dca ("PCI: rewrite PCI BAR reading code") masked off
low-order bits from 'l', but not from 'sz'.  Both are passed to pci_size(),
which compares 'base == maxbase' to check for read-only BARs.  The masking
of 'l' means that comparison will never be 'true', so the check for
read-only BARs no longer works.

Resolve this by also masking off the low-order bits of 'sz' before passing
it into pci_size() as 'maxbase'.  With this change, pci_size() will once
again catch the problems that have been encountered to date:

  - AGP aperture BAR of AMD-7xx host bridges: if the AGP window is
    disabled, this BAR is read-only and read as 0x00000008 [1]

  - BARs 0-4 of ALi IDE controllers can be non-zero and read-only [1]

  - Intel Sandy Bridge - Thermal Management Controller [8086:0103];
    BAR 0 returning 0xfed98004 [2]

  - Intel Xeon E5 v3/Core i7 Power Control Unit [8086:2fc0];
    Bar 0 returning 0x00001a [3]

Link: [1] https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/drivers/pci/probe.c?id=1307ef6621991f1c4bc3cec1b5a4ebd6fd3d66b9 ("PCI: probing read-only BARs" (pre-git))
Link: [2] https://bugzilla.kernel.org/show_bug.cgi?id=43331
Link: [3] https://bugzilla.kernel.org/show_bug.cgi?id=85991
Reported-by: William Unruh &lt;unruh@physics.ubc.ca&gt;
Reported-by: Martin Lucina &lt;martin@lucina.net&gt;
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
CC: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 36e8164882ca6d3c41cb91e6f09a3ed236841f80 upstream.

Commit 6ac665c63dca ("PCI: rewrite PCI BAR reading code") masked off
low-order bits from 'l', but not from 'sz'.  Both are passed to pci_size(),
which compares 'base == maxbase' to check for read-only BARs.  The masking
of 'l' means that comparison will never be 'true', so the check for
read-only BARs no longer works.

Resolve this by also masking off the low-order bits of 'sz' before passing
it into pci_size() as 'maxbase'.  With this change, pci_size() will once
again catch the problems that have been encountered to date:

  - AGP aperture BAR of AMD-7xx host bridges: if the AGP window is
    disabled, this BAR is read-only and read as 0x00000008 [1]

  - BARs 0-4 of ALi IDE controllers can be non-zero and read-only [1]

  - Intel Sandy Bridge - Thermal Management Controller [8086:0103];
    BAR 0 returning 0xfed98004 [2]

  - Intel Xeon E5 v3/Core i7 Power Control Unit [8086:2fc0];
    Bar 0 returning 0x00001a [3]

Link: [1] https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/drivers/pci/probe.c?id=1307ef6621991f1c4bc3cec1b5a4ebd6fd3d66b9 ("PCI: probing read-only BARs" (pre-git))
Link: [2] https://bugzilla.kernel.org/show_bug.cgi?id=43331
Link: [3] https://bugzilla.kernel.org/show_bug.cgi?id=85991
Reported-by: William Unruh &lt;unruh@physics.ubc.ca&gt;
Reported-by: Martin Lucina &lt;martin@lucina.net&gt;
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
CC: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Generate uppercase hex for modalias interface class</title>
<updated>2015-02-02T09:04:38+00:00</updated>
<author>
<name>Ricardo Ribalda Delgado</name>
<email>ricardo.ribalda@gmail.com</email>
</author>
<published>2014-08-27T12:57:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7a6185a12d7bc28267a0917b2cb41e8eb8adb24f'/>
<id>7a6185a12d7bc28267a0917b2cb41e8eb8adb24f</id>
<content type='text'>
commit 89ec3dcf17fd3fa009ecf8faaba36828dd6bc416 upstream.

Some implementations of modprobe fail to load the driver for a PCI device
automatically because the "interface" part of the modalias from the kernel
is lowercase, and the modalias from file2alias is uppercase.

The "interface" is the low-order byte of the Class Code, defined in PCI
r3.0, Appendix D.  Most interface types defined in the spec do not use
alpha characters, so they won't be affected.  For example, 00h, 01h, 10h,
20h, etc. are unaffected.

Print the "interface" byte of the Class Code in uppercase hex, as we
already do for the Vendor ID, Device ID, Class, etc.

[bhelgaas: changelog]
Signed-off-by: Ricardo Ribalda Delgado &lt;ricardo.ribalda@gmail.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 89ec3dcf17fd3fa009ecf8faaba36828dd6bc416 upstream.

Some implementations of modprobe fail to load the driver for a PCI device
automatically because the "interface" part of the modalias from the kernel
is lowercase, and the modalias from file2alias is uppercase.

The "interface" is the low-order byte of the Class Code, defined in PCI
r3.0, Appendix D.  Most interface types defined in the spec do not use
alpha characters, so they won't be affected.  For example, 00h, 01h, 10h,
20h, etc. are unaffected.

Print the "interface" byte of the Class Code in uppercase hex, as we
already do for the Vendor ID, Device ID, Class, etc.

[bhelgaas: changelog]
Signed-off-by: Ricardo Ribalda Delgado &lt;ricardo.ribalda@gmail.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Increase IBM ipr SAS Crocodile BARs to at least system page size</title>
<updated>2015-02-02T09:04:37+00:00</updated>
<author>
<name>Douglas Lehr</name>
<email>dllehr@us.ibm.com</email>
</author>
<published>2014-08-20T23:26:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a66b378950318cc5ab9be8eb3f21dd2383ae18b9'/>
<id>a66b378950318cc5ab9be8eb3f21dd2383ae18b9</id>
<content type='text'>
commit 9fe373f9997b48fcd6222b95baf4a20c134b587a upstream.

The Crocodile chip occasionally comes up with 4k and 8k BAR sizes.  Due to
an erratum, setting the SR-IOV page size causes the physical function BARs
to expand to the system page size.  Since ppc64 uses 64k pages, when Linux
tries to assign the smaller resource sizes to the now 64k BARs the address
will be truncated and the BARs will overlap.

Force Linux to allocate the resource as a full page, which avoids the
overlap.

[bhelgaas: print expanded resource, too]
Signed-off-by: Douglas Lehr &lt;dllehr@us.ibm.com&gt;
Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Milton Miller &lt;miltonm@us.ibm.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9fe373f9997b48fcd6222b95baf4a20c134b587a upstream.

The Crocodile chip occasionally comes up with 4k and 8k BAR sizes.  Due to
an erratum, setting the SR-IOV page size causes the physical function BARs
to expand to the system page size.  Since ppc64 uses 64k pages, when Linux
tries to assign the smaller resource sizes to the now 64k BARs the address
will be truncated and the BARs will overlap.

Force Linux to allocate the resource as a full page, which avoids the
overlap.

[bhelgaas: print expanded resource, too]
Signed-off-by: Douglas Lehr &lt;dllehr@us.ibm.com&gt;
Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Milton Miller &lt;miltonm@us.ibm.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: pciehp: Prevent NULL dereference during probe</title>
<updated>2015-02-02T09:04:37+00:00</updated>
<author>
<name>Andreas Noever</name>
<email>andreas.noever@gmail.com</email>
</author>
<published>2014-09-16T21:16:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7cf009d054e48bea3eb70af362d8c58b22baadec'/>
<id>7cf009d054e48bea3eb70af362d8c58b22baadec</id>
<content type='text'>
commit bceee4a97eb58bd0e80e39eff11b506ddd9e7ad3 upstream.

pciehp assumes that dev-&gt;subordinate, the struct pci_bus for a bridge's
secondary bus, exists.  But we do not create that bus if we run out of bus
numbers during enumeration.  This leads to a NULL dereference in
init_slot() (and other places).

Change pciehp_probe() to return -ENODEV when no secondary bus is present.

Signed-off-by: Andreas Noever &lt;andreas.noever@gmail.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit bceee4a97eb58bd0e80e39eff11b506ddd9e7ad3 upstream.

pciehp assumes that dev-&gt;subordinate, the struct pci_bus for a bridge's
secondary bus, exists.  But we do not create that bus if we run out of bus
numbers during enumeration.  This leads to a NULL dereference in
init_slot() (and other places).

Change pciehp_probe() to return -ENODEV when no secondary bus is present.

Signed-off-by: Andreas Noever &lt;andreas.noever@gmail.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Fix incorrect vgaarb conditional in WARN_ON()</title>
<updated>2014-07-07T01:49:19+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2014-04-05T21:14:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5564b79b5e7c10fbbca517d74f7f0d77877c4270'/>
<id>5564b79b5e7c10fbbca517d74f7f0d77877c4270</id>
<content type='text'>
commit 67ebd8140dc8923c65451fa0f6a8eee003c4dcd3 upstream.

3448a19da479 "vgaarb: use bridges to control VGA routing where possible"
added the "flags &amp; PCI_VGA_STATE_CHANGE_DECODES" condition to an existing
WARN_ON(), but used bitwise AND (&amp;) instead of logical AND (&amp;&amp;), so the
condition is never true.  Replace with logical AND.

Found by Coverity (CID 142811).

Fixes: 3448a19da479 "vgaarb: use bridges to control VGA routing where possible"
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
Acked-by: David Airlie &lt;airlied@redhat.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 67ebd8140dc8923c65451fa0f6a8eee003c4dcd3 upstream.

3448a19da479 "vgaarb: use bridges to control VGA routing where possible"
added the "flags &amp; PCI_VGA_STATE_CHANGE_DECODES" condition to an existing
WARN_ON(), but used bitwise AND (&amp;) instead of logical AND (&amp;&amp;), so the
condition is never true.  Replace with logical AND.

Found by Coverity (CID 142811).

Fixes: 3448a19da479 "vgaarb: use bridges to control VGA routing where possible"
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
Acked-by: David Airlie &lt;airlied@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Add new ID for Intel GPU "spurious interrupt" quirk</title>
<updated>2014-07-07T01:49:19+00:00</updated>
<author>
<name>Thomas Jarosch</name>
<email>thomas.jarosch@intra2net.com</email>
</author>
<published>2014-04-07T13:10:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ade14072dca4bafc463c63a1788d3792af7fed54'/>
<id>ade14072dca4bafc463c63a1788d3792af7fed54</id>
<content type='text'>
commit 7c82126a94e69bbbac586f0249e7ef11e681246c upstream.

After a CPU upgrade while keeping the same mainboard, we faced "spurious
interrupt" problems again.

It turned out that the new CPU also featured a new GPU with a different PCI
ID.

Add this PCI ID to the quirk table.  Probably all other Intel GPU PCI IDs
are affected, too, but I don't want to add them without a test system.

See f67fd55fa96f ("PCI: Add quirk for still enabled interrupts on Intel
Sandy Bridge GPUs") for some history.

[bhelgaas: add f67fd55fa96f reference, stable tag]
Signed-off-by: Thomas Jarosch &lt;thomas.jarosch@intra2net.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 7c82126a94e69bbbac586f0249e7ef11e681246c upstream.

After a CPU upgrade while keeping the same mainboard, we faced "spurious
interrupt" problems again.

It turned out that the new CPU also featured a new GPU with a different PCI
ID.

Add this PCI ID to the quirk table.  Probably all other Intel GPU PCI IDs
are affected, too, but I don't want to add them without a test system.

See f67fd55fa96f ("PCI: Add quirk for still enabled interrupts on Intel
Sandy Bridge GPUs") for some history.

[bhelgaas: add f67fd55fa96f reference, stable tag]
Signed-off-by: Thomas Jarosch &lt;thomas.jarosch@intra2net.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/ASPM: Don't touch ASPM if forcibly disabled</title>
<updated>2014-06-07T23:02:15+00:00</updated>
<author>
<name>Joe Lawrence</name>
<email>joe.lawrence@stratus.com</email>
</author>
<published>2013-01-15T20:31:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=359c6340faa39167666c0e9b9f44ad54a521c409'/>
<id>359c6340faa39167666c0e9b9f44ad54a521c409</id>
<content type='text'>
commit a26d5ecb3201c11e03663a8f4a7dedc0c5f85c07 upstream.

Don't allocate and track PCIe ASPM state when "pcie_aspm=off" is specified
on the kernel command line.

Based-on-patch-from: Matthew Garrett &lt;mjg59@srcf.ucam.org&gt;
Signed-off-by: Joe Lawrence &lt;joe.lawrence@stratus.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: David Bulkow &lt;david.bulkow@stratus.com&gt;
Acked-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
[wyj: Backported to 3.4: context adjust]
Signed-off-by: Yijing Wang &lt;wangyijing@huawei.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 a26d5ecb3201c11e03663a8f4a7dedc0c5f85c07 upstream.

Don't allocate and track PCIe ASPM state when "pcie_aspm=off" is specified
on the kernel command line.

Based-on-patch-from: Matthew Garrett &lt;mjg59@srcf.ucam.org&gt;
Signed-off-by: Joe Lawrence &lt;joe.lawrence@stratus.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: David Bulkow &lt;david.bulkow@stratus.com&gt;
Acked-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
[wyj: Backported to 3.4: context adjust]
Signed-off-by: Yijing Wang &lt;wangyijing@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: shpchp: Use per-slot workqueues to avoid deadlock</title>
<updated>2014-06-07T23:02:07+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2013-01-11T19:21:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=51a937d48eee52b33ba1f2feb2b8b40d254800c9'/>
<id>51a937d48eee52b33ba1f2feb2b8b40d254800c9</id>
<content type='text'>
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 &lt;wangyijing@huawei.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
[hq: Backported to 3.4: adjust context]
Signed-off-by: Qiang Huang &lt;h.huangqiang@huawei.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 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 &lt;wangyijing@huawei.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
[hq: Backported to 3.4: adjust context]
Signed-off-by: Qiang Huang &lt;h.huangqiang@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: shpchp: Check bridge's secondary (not primary) bus speed</title>
<updated>2014-06-07T23:02:03+00:00</updated>
<author>
<name>Marcel Apfelbaum</name>
<email>marcel.a@redhat.com</email>
</author>
<published>2014-05-15T18:42:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e5cc5b9c0f4acab5757785706528010288b52c2c'/>
<id>e5cc5b9c0f4acab5757785706528010288b52c2c</id>
<content type='text'>
commit 93fa9d32670f5592c8e56abc9928fc194e1e72fc upstream.

When a new device is added below a hotplug bridge, the bridge's secondary
bus speed and the device's bus speed must match.  The shpchp driver
previously checked the bridge's *primary* bus speed, not the secondary bus
speed.

This caused hot-add errors like:

  shpchp 0000:00:03.0: Speed of bus ff and adapter 0 mismatch

Check the secondary bus speed instead.

[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75251
Fixes: 3749c51ac6c1 ("PCI: Make current and maximum bus speeds part of the PCI core")
Signed-off-by: Marcel Apfelbaum &lt;marcel.a@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Michael S. Tsirkin &lt;mst@redhat.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 93fa9d32670f5592c8e56abc9928fc194e1e72fc upstream.

When a new device is added below a hotplug bridge, the bridge's secondary
bus speed and the device's bus speed must match.  The shpchp driver
previously checked the bridge's *primary* bus speed, not the secondary bus
speed.

This caused hot-add errors like:

  shpchp 0000:00:03.0: Speed of bus ff and adapter 0 mismatch

Check the secondary bus speed instead.

[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75251
Fixes: 3749c51ac6c1 ("PCI: Make current and maximum bus speeds part of the PCI core")
Signed-off-by: Marcel Apfelbaum &lt;marcel.a@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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