commit: c9651e70ad0aa499814817cbf3cc1d0b806ed3a1
From: Matthew Garrett <[email protected]>
Date: Tue, 27 Mar 2012 10:17:41 -0400
Subject: ASPM: Fix pcie devices with non-pcie children
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 <[email protected]> # kernel panic
Reported-by: Chris Holland <[email protected]> # disk detection trouble
Signed-off-by: Matthew Garrett <[email protected]>
Cc: [email protected]
Tested-by: Hatem Masmoudi <[email protected]> # Dell Latitude E5520
Tested-by: janek <[email protected]> # pata_jmicron with JMB362/JMB363
[jn: with more symptoms in log message]
Signed-off-by: Jonathan Nieder <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
---
drivers/pci/pcie/aspm.c | 13 ++++++++++---
1 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 4bdef24..b500840 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -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
--
1.7.3.4
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