3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alex Deucher <alexander.deucher@xxxxxxx> commit 05082b8bbd1a0ffc74235449c4b8930a8c240f85 upstream. When executing in a PCI passthrough based virtuzliation environment, the hypervisor will usually attempt to send a PCIe bus reset signal to the ASIC when the VM reboots. In this scenario, the card is not correctly initialized, but we still consider it to be posted. Therefore, in a passthrough based environemnt we should always post the card to guarantee it is in a good state for driver initialization. Ported from amdgpu commit: amdgpu: fix asic initialization for virtualized environments Cc: Andres Rodriguez <andres.rodriguez@xxxxxxx> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/gpu/drm/radeon/radeon_device.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -598,6 +598,23 @@ void radeon_gtt_location(struct radeon_d /* * GPU helpers function. */ + +/** + * radeon_device_is_virtual - check if we are running is a virtual environment + * + * Check if the asic has been passed through to a VM (all asics). + * Used at driver startup. + * Returns true if virtual or false if not. + */ +static bool radeon_device_is_virtual(void) +{ +#ifdef CONFIG_X86 + return boot_cpu_has(X86_FEATURE_HYPERVISOR); +#else + return false; +#endif +} + /** * radeon_card_posted - check if the hw has already been initialized * @@ -611,6 +628,10 @@ bool radeon_card_posted(struct radeon_de { uint32_t reg; + /* for pass through, always force asic_init */ + if (radeon_device_is_virtual()) + return false; + /* required for EFI mode on macbook2,1 which uses an r5xx asic */ if (efi_enabled(EFI_BOOT) && (rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) && -- 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