Am 23.11.2016 um 02:22 schrieb Peter Wu: > When PCIe port PM is not enabled (system BIOS is pre-2015 or the > pcie_port_pm=off parameter is set), legacy ATPX PM should still be > marked as supported. Otherwise the GPU can fail to power on after > runtime suspend. This affected a Dell Inspiron 5548. > > Ideally the BIOS date in the PCI core is lowered to 2013 (the first year > where hybrid graphics platforms using power resources was introduced), > but that seems more risky at this point and would not solve the > pcie_port_pm=off issue. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98505 > Reported-and-tested-by: Nayan Deshmukh <nayan26deshmukh at gmail.com> > Signed-off-by: Peter Wu <peter at lekensteyn.nl> Even when lowering the BIOS date this sounds reasonable to me in the case of pcie_port_pm=off. But since I'm not very deep into power management the patch is only Acked-by: Christian König <christian.koenig at amd.com>. Regards, Christian. > --- > Hi, > > This patch is already three weeks old. One alternative idea was lowering BIOS > date in PCI core, but as pcie_port_pm=force did not have the desired effect, I > do not think that this would help though. > > I have also not contacted linux-pci or Mika about lowering the year due to the > lack of a good reason. Might do it later though once ACPICA bug 1333 is sorted > out such that lowering the year actually has benefits for a Nvidia laptop (or if > some amdgpu problem can be solved by this). > > Both patches should probably be Cc stable (4.8+), fixing 2f5af82eeab2 and > b8c9fd5ad4b4 ("track whether if this is a hybrid graphics platform"). There have > been some ifdef 0's and reverts in between, so I was not sure if adding the > Fixes tag is appropriate. > > Kind regards, > Peter > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c > index 10b5ddf..951addf 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c > @@ -33,6 +33,7 @@ struct amdgpu_atpx { > > static struct amdgpu_atpx_priv { > bool atpx_detected; > + bool bridge_pm_usable; > /* handle for device - and atpx */ > acpi_handle dhandle; > acpi_handle other_handle; > @@ -200,7 +201,11 @@ static int amdgpu_atpx_validate(struct amdgpu_atpx *atpx) > atpx->is_hybrid = false; > if (valid_bits & ATPX_MS_HYBRID_GFX_SUPPORTED) { > printk("ATPX Hybrid Graphics\n"); > - atpx->functions.power_cntl = false; > + /* > + * Disable legacy PM methods only when pcie port PM is usable, > + * otherwise the device might fail to power off or power on. > + */ > + atpx->functions.power_cntl = !amdgpu_atpx_priv.bridge_pm_usable; > atpx->is_hybrid = true; > } > > @@ -471,6 +476,7 @@ static int amdgpu_atpx_power_state(enum vga_switcheroo_client_id id, > */ > static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev) > { > + struct pci_dev *parent_pdev = pci_upstream_bridge(pdev); > acpi_handle dhandle, atpx_handle; > acpi_status status; > > @@ -485,6 +491,7 @@ static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev) > } > amdgpu_atpx_priv.dhandle = dhandle; > amdgpu_atpx_priv.atpx.handle = atpx_handle; > + amdgpu_atpx_priv.bridge_pm_usable = parent_pdev && parent_pdev->bridge_d3; > return true; > } >
