On Fri, Feb 24, 2017 at 1:19 PM, Lukas Wunner <lukas@xxxxxxxxx> wrote: > An external Thunderbolt GPU can neither drive the laptop's panel nor be > powered off by the platform, so there's no point in registering it with > vga_switcheroo. > In fact, when the external GPU is runtime suspended, > vga_switcheroo will cut power to the internal discrete GPU, resulting in > a lockup. Why does suspending the external GPU cause vga_switcheroo to cut power to the internal GPU? No doubt this would be obvious to a GPU person, which I definitely am not. > Cc: Ben Skeggs <bskeggs@xxxxxxxxxx> > Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> > --- > drivers/gpu/drm/nouveau/nouveau_vga.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_vga.c b/drivers/gpu/drm/nouveau/nouveau_vga.c > index eef22c6b9665..c2a7fd606c2e 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_vga.c > +++ b/drivers/gpu/drm/nouveau/nouveau_vga.c > @@ -95,6 +95,10 @@ nouveau_vga_init(struct nouveau_drm *drm) > > vga_client_register(dev->pdev, dev, NULL, nouveau_vga_set_decode); > > + /* don't register Thunderbolt eGPU with vga_switcheroo */ > + if (pci_is_thunderbolt_attached(dev->pdev)) > + return; I guess there's no way to move this inside vga_switcheroo_register_client() instead of putting the test in all the drivers? > + > if (nouveau_runtime_pm == 1) > runtime = true; > if ((nouveau_runtime_pm == -1) && (nouveau_is_optimus() || nouveau_is_v1_dsm())) > @@ -111,6 +115,11 @@ nouveau_vga_fini(struct nouveau_drm *drm) > struct drm_device *dev = drm->dev; > bool runtime = false; > > + vga_client_register(dev->pdev, NULL, NULL, NULL); > + > + if (pci_is_thunderbolt_attached(dev->pdev)) > + return; > + > if (nouveau_runtime_pm == 1) > runtime = true; > if ((nouveau_runtime_pm == -1) && (nouveau_is_optimus() || nouveau_is_v1_dsm())) > @@ -119,7 +128,6 @@ nouveau_vga_fini(struct nouveau_drm *drm) > vga_switcheroo_unregister_client(dev->pdev); > if (runtime && nouveau_is_v1_dsm() && !nouveau_is_optimus()) > vga_switcheroo_fini_domain_pm_ops(drm->dev->dev); > - vga_client_register(dev->pdev, NULL, NULL, NULL); The amd & radeon patches look like this: - vga_switcheroo_unregister_client(rdev->pdev); + if (!pci_is_thunderbolt_attached(adev->pdev)) + vga_switcheroo_unregister_client(adev->pdev); This nouveau patch looks suspiciously different. But again, I'm not a GPU guy so all I can really say is "hmm, I wonder why it's different?" > } > > > -- > 2.11.0 > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
