Hi,
Here are two patches to fix an issue reported on kernel bugzilla (infinite loop due to unchecked function) and a more important fix to fix hanging Optimus machines when runtime PM is enabled (with pm/pci patches).
An older (obsolete) patch for the first issue was tested by the reporter: https://bugzilla.kernel.org/show_bug.cgi?id=104791#c11 (it is replaced by "check for function 0x1B before using it").
The second issue will occur when: - A modern Optimus laptop is in use (designed for Windows 8 or newer). - nouveau runtime PM is enabled (1 or the default -1). - The patch "PCI: Add runtime PM support for PCIe ports" from Mika is pulled into v4.7 (or v4.8[1]?) via the pci/pm branch, https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/commit/?h=pci/p... (see also the discussion for "[PATCH] PCI: Power on bridges before scanning new devices" at http://article.gmane.org/gmane.linux.power-management.general/76411)
The first two patches are just refactoring to reduce code duplication (and scratch an itch) and make the following patches possible. The next two patches fix the problems reported above.
I intend to get these patches in 4.7 (or the first version where pci/pm gets merged) to avoid a lockup when runpm is enabled. Note: - If the fourth patch is merged before/without Mika's PCIe port patch, then those modern Optimus machines above will not be put into D3cold. - If the fourth patch is not merged (or merged after Mika's patch), then under the above conditions the affected machine can lock up. - The three other patches are unrelated to this issue and can safely be merged.
Tested with: - Linux v4.6 + pci/pm + these four patches - Hardware: Clevo P651RA with acpi_osi="!Windows 2015" (the latter is a workaround for another PCIe issue). - Card is asleep, woke up with lspci, waited a bit and retried/suspended: - # lspci -xxxxnnvvvv >/dev/null; sleep 5 - # lspci -xxxxnnvvvv >/dev/null; sleep 5; systemctl suspend - # lspci -xxxxnnvvvv >/dev/null; systemctl suspend
Kind regards, Peter
[1]: https://lkml.kernel.org/r/20160524211309.GH1789@lahna.fi.intel.com
Peter Wu (4): drm/nouveau/acpi: ensure matching ACPI handle and supported functions drm/nouveau/acpi: return supported DSM functions drm/nouveau/acpi: check for function 0x1B before using it drm/nouveau/acpi: fix lockup with PCIe runtime PM
drivers/gpu/drm/nouveau/nouveau_acpi.c | 100 +++++++++++++++++++++------------ 1 file changed, 63 insertions(+), 37 deletions(-)