| From c9651e70ad0aa499814817cbf3cc1d0b806ed3a1 Mon Sep 17 00:00:00 2001 |
| From: Matthew Garrett <mjg@redhat.com> |
| Date: Tue, 27 Mar 2012 10:17:41 -0400 |
| Subject: ASPM: Fix pcie devices with non-pcie children |
| |
| From: Matthew Garrett <mjg@redhat.com> |
| |
| commit c9651e70ad0aa499814817cbf3cc1d0b806ed3a1 upstream. |
| |
| 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> |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/pci/pcie/aspm.c | 13 ++++++++++--- |
| 1 file changed, 10 insertions(+), 3 deletions(-) |
| |
| --- a/drivers/pci/pcie/aspm.c |
| +++ b/drivers/pci/pcie/aspm.c |
| @@ -500,9 +500,6 @@ static int pcie_aspm_sanity_check(struct |
| 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 |
| @@ -511,6 +508,16 @@ static int pcie_aspm_sanity_check(struct |
| 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 |