---------- Forwarded message ---------- From: <bugzilla-daemon@xxxxxxxxxxxxxxxxxxx> Date: Thu, Mar 14, 2013 at 4:04 AM Subject: [Bug 55211] New: pci_disable_link_state PCIE_LINK_STATE_L0S no longer disables ASPM for ath5k To: bhelgaas@xxxxxxxxxx https://bugzilla.kernel.org/show_bug.cgi?id=55211 Summary: pci_disable_link_state PCIE_LINK_STATE_L0S no longer disables ASPM for ath5k Product: Drivers Version: 2.5 Kernel Version: 3.8.0 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: PCI AssignedTo: drivers_pci@xxxxxxxxxxxxxxxxxxxx ReportedBy: roman.yepishev@xxxxxxxxx Regression: Yes This bug report is based on investigation for https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1137513 I have an old Acer Aspire One AOA150 netbook which has a BIOS that does not disable ASPM for ath5k wireless device, 168c:001c, Atheros Communications Inc. AR242x / AR542x PCI-Express adapter. 2 years ago in 6ccf15a1a76d2ff915cdef6ae4d12d0170087118 ath5k driver got this: pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S); The card was working fine until Ubuntu raring 13.04 switched to 3.8 and the same symptoms that were fixed by the commit above started to appear - random md5 generator instead of file downloads, SSH disconnects, etc. The card had LnkCtl: ASPM L0s L1 Enabled; according to lspci in 3.8+ while it had ASPM disabled in kernels <= 3.7. I have tested all the available builds of 3.8 mainline kernel and found that it was introduced early in 3.8 series. Then I did a bisect between 3.7 and 3.8 and found that the first bad commit is: commit 8c33f51df406e1a1f7fa4e9b244845b7ebd61fa6 Author: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx> Date: Tue Oct 30 15:27:13 2012 +0900 PCI/ACPI: Request _OSC control before scanning PCI root bus This patch moves up the code block to request _OSC control in order to separate ACPI work and PCI work in acpi_pci_root_add(). Signed-off-by: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> I see the following in dmesg: [ 0.145833] pci_root PNP0A08:00: ACPI _OSC support notification failed, disabling PCIe ASPM [ 0.145840] pci_root PNP0A08:00: Unable to request _OSC control (_OSC support mask: 0x08) ... [ 0.181256] ACPI _OSC control for PCIe not granted, disabling ASPM So it looks like it is actually doing something, yet ASPM remains enabled causing the card to malfunction during data transfers. -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
