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ASPM: Fix pcie devices with non-pcie children

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Since 3.2.12 and 3.3, some systems are failing to boot with a BUG_ON.
Some other systems using the pata_jmicron driver fail to boot because no
disks are detected.  Passing pcie_aspm=force on the kernel command line
works around it.

The cause: commit 4949be16822e ("PCI: ignore pre-1.1 ASPM quirking when
ASPM is disabled") changed the behaviour of pcie_aspm_sanity_check() to
always return 0 if aspm is disabled, in order to avoid cases where we
changed ASPM state on pre-PCIe 1.1 devices.

This skipped the secondary function of pcie_aspm_sanity_check which was
to avoid us enabling ASPM on devices that had non-PCIe children, causing
trouble later on.  Move the aspm_disabled check so we continue to honour
that scenario.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=42979 and
          http://bugs.debian.org/665420

Reported-by: Romain Francoise <romain@orebokech.com> # kernel panic
Reported-by: Chris Holland <bandidoirlandes@gmail.com> # disk detection trouble
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Tested-by: Hatem Masmoudi <hatem.masmoudi@gmail.com> # Dell Latitude E5520
Tested-by: janek <jan0x6c@gmail.com> # pata_jmicron with JMB362/JMB363
[jn: with more symptoms in log message]
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Garrett 2012-03-27 10:17:41 -04:00 committed by Linus Torvalds
parent cdb0f9a1ad
commit c9651e70ad
1 changed files with 10 additions and 3 deletions
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13
drivers/pci/pcie/aspm.c
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@ -508,9 +508,6 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
int pos;
u32 reg32;
if (aspm_disabled)
return 0;
/*
* Some functions in a slot might not all be PCIe functions,
* very strange. Disable ASPM for the whole slot
@ -519,6 +516,16 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
pos = pci_pcie_cap(child);
if (!pos)
return -EINVAL;
/*
* If ASPM is disabled then we're not going to change
* the BIOS state. It's safe to continue even if it's a
* pre-1.1 device
*/
if (aspm_disabled)
continue;
/*
* Disable ASPM for pre-1.1 PCIe device, we follow MS to use
* RBER bit to determine if a function is 1.1 version device