This is a note to let you know that I've just added the patch titled drm/amdgpu: fix check for port PM availability to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amdgpu-fix-check-for-port-pm-availability.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 7ac33e47d5769632010e537964c7e45498f8dc26 Mon Sep 17 00:00:00 2001 From: Peter Wu <peter@xxxxxxxxxxxxx> Date: Sat, 26 Nov 2016 15:05:01 +0100 Subject: drm/amdgpu: fix check for port PM availability From: Peter Wu <peter@xxxxxxxxxxxxx> commit 7ac33e47d5769632010e537964c7e45498f8dc26 upstream. The ATPX method does not always exist on the dGPU, it may be located at the iGPU. The parent device of the iGPU is the root port for which bridge_d3 is false. This accidentally enables the legacy PM method which conflicts with port PM and prevented the dGPU from powering on. Fixes: 1db4496f167b ("drm/amdgpu: fix power state when port pm is unavailable") Reported-and-tested-by: Mike Lothian <mike@xxxxxxxxxxxxxx> Signed-off-by: Peter Wu <peter@xxxxxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c @@ -476,7 +476,6 @@ static int amdgpu_atpx_power_state(enum */ 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; @@ -491,7 +490,6 @@ static bool amdgpu_atpx_pci_probe_handle } 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; } @@ -553,17 +551,25 @@ static bool amdgpu_atpx_detect(void) struct pci_dev *pdev = NULL; bool has_atpx = false; int vga_count = 0; + bool d3_supported = false; + struct pci_dev *parent_pdev; while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) { vga_count++; has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true); + + parent_pdev = pci_upstream_bridge(pdev); + d3_supported |= parent_pdev && parent_pdev->bridge_d3; } while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) { vga_count++; has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true); + + parent_pdev = pci_upstream_bridge(pdev); + d3_supported |= parent_pdev && parent_pdev->bridge_d3; } if (has_atpx && vga_count == 2) { @@ -571,6 +577,7 @@ static bool amdgpu_atpx_detect(void) printk(KERN_INFO "vga_switcheroo: detected switching method %s handle\n", acpi_method_name); amdgpu_atpx_priv.atpx_detected = true; + amdgpu_atpx_priv.bridge_pm_usable = d3_supported; amdgpu_atpx_init(); return true; } Patches currently in stable-queue which might be from peter@xxxxxxxxxxxxx are queue-4.8/drm-radeon-fix-power-state-when-port-pm-is-unavailable-v2.patch queue-4.8/drm-amdgpu-fix-power-state-when-port-pm-is-unavailable.patch queue-4.8/drm-radeon-fix-check-for-port-pm-availability.patch queue-4.8/drm-amdgpu-fix-check-for-port-pm-availability.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html