From: Matthew Garrett Date: Tue, 27 Mar 2012 14:17:41 +0000 (-0400) Subject: ASPM: Fix pcie devices with non-pcie children X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=c9651e70ad0aa499814817cbf3cc1d0b806ed3a1;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git 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 # kernel panic Reported-by: Chris Holland # disk detection trouble Signed-off-by: Matthew Garrett Cc: stable@vger.kernel.org Tested-by: Hatem Masmoudi # Dell Latitude E5520 Tested-by: janek # pata_jmicron with JMB362/JMB363 [jn: with more symptoms in log message] Signed-off-by: Jonathan Nieder Signed-off-by: Linus Torvalds --- diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 4bdef24cd412..b500840a143b 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