lkml.org 
[lkml]   [2013]   [Aug]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] ACPI: Fix osc flag setup ordering to allow pcie hotplug use when available
On Mon, Aug 26, 2013 at 11:36:21AM -0400, Neil Horman wrote:
> From: root <root@dhcp47-16.lab.bos.redhat.com>
>
> Somewhere between 3.9 and 3.10 it seems the order in which pcie and acpi probed
> slots for hotplug capabilites got reversed. While this isn't a big deal, it did
> uncover a bug in the ACPI bus setup path. Specifically, acpi_pci_root_add calls
> pci_acpi_scan_root before setting the osc flags for the device handle.
> pci_acpi_scan_root, among other things uses device_is_managed_by_native_pciehp()
> to determine if a given slot has pcie hotplug capabilties, whcih checks the
> devices OSC_PCI_EXPRESS_NATIVE_HP_CONTROL flag. Since that flag is not set
> until after pci_acpi_scan_root_completes, the acpi code never sees that pcie
> slots are hotplug capable and configures them all to use acpi instead.
>
> Fix is pretty simple, just defer the scan until after the osc flags have been
> set on the device. Tested by myself and it seems to work well.
>
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> CC: Len Brown <lenb@kernel.org>
> CC: "Rafael J. Wysocki" <rjw@sisk.pl>
> CC: Bjorn Helgaas <bhelgaas@google.com>
> CC: linux-acpi@vger.kernel.org
> CC: linux-pci@vger.kernel.org
>
Sorry, self NAK on this, sorry, I forgot to fix up authorship from my
development machine. I'll resend in a second.
Neil


\
 
 \ /
  Last update: 2013-08-26 18:01    [W:0.158 / U:0.752 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site