From: Mario Limonciello mario.limonciello@amd.com
commit 08fffa74d9772d9538338be3f304006c94dde6f0 upstream.
Users report a white flickering screen on multiple systems that is tied to having 64GB or more memory. When S/G is enabled pages will get pinned to both VRAM carve out and system RAM leading to this.
Until it can be fixed properly, disable S/G when 64GB of memory or more is detected. This will force pages to be pinned into VRAM. This should fix white screen flickers but if VRAM pressure is encountered may lead to black screens. It's a trade-off for now.
Fixes: 81d0bcf99009 ("drm/amdgpu: make display pinning more flexible (v2)") Cc: Hamza Mahfooz Hamza.Mahfooz@amd.com Cc: Roman Li roman.li@amd.com Cc: stable@vger.kernel.org # 6.1.y: bf0207e172703 ("drm/amdgpu: add S/G display parameter") Cc: stable@vger.kernel.org # 6.4.y Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2735 Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2354 Signed-off-by: Mario Limonciello mario.limonciello@amd.com Reviewed-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 26 ++++++++++++++++++++++ drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 +--- 3 files changed, 29 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -1246,6 +1246,7 @@ int amdgpu_device_gpu_recover(struct amd void amdgpu_device_pci_config_reset(struct amdgpu_device *adev); int amdgpu_device_pci_reset(struct amdgpu_device *adev); bool amdgpu_device_need_post(struct amdgpu_device *adev); +bool amdgpu_sg_display_supported(struct amdgpu_device *adev); bool amdgpu_device_pcie_dynamic_switching_supported(void); bool amdgpu_device_should_use_aspm(struct amdgpu_device *adev); bool amdgpu_device_aspm_support_quirk(void); --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -1353,6 +1353,32 @@ bool amdgpu_device_need_post(struct amdg }
/* + * On APUs with >= 64GB white flickering has been observed w/ SG enabled. + * Disable S/G on such systems until we have a proper fix. + * https://gitlab.freedesktop.org/drm/amd/-/issues/2354 + * https://gitlab.freedesktop.org/drm/amd/-/issues/2735 + */ +bool amdgpu_sg_display_supported(struct amdgpu_device *adev) +{ + switch (amdgpu_sg_display) { + case -1: + break; + case 0: + return false; + case 1: + return true; + default: + return false; + } + if ((totalram_pages() << (PAGE_SHIFT - 10)) + + (adev->gmc.real_vram_size / 1024) >= 64000000) { + DRM_WARN("Disabling S/G due to >=64GB RAM\n"); + return false; + } + return true; +} + +/* * Intel hosts such as Raptor Lake and Sapphire Rapids don't support dynamic * speed switching. Until we have confirmation from Intel that a specific host * supports it, it's safer that we keep it disabled for all. --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1630,9 +1630,8 @@ static int amdgpu_dm_init(struct amdgpu_ } break; } - if (init_data.flags.gpu_vm_support && - (amdgpu_sg_display == 0)) - init_data.flags.gpu_vm_support = false; + if (init_data.flags.gpu_vm_support) + init_data.flags.gpu_vm_support = amdgpu_sg_display_supported(adev);
if (init_data.flags.gpu_vm_support) adev->mode_info.gpu_vm_support = true;