From 324e4e833783474043fdc2cd1671d421399ec0cf Mon Sep 17 00:00:00 2001 From: Harry Wentland Date: Tue, 8 May 2018 11:33:42 -0400 Subject: [PATCH 4698/5725] drm/amdgpu: Don't default to DC support for Kaveri and older We've had a number of users report failures to detect and light up display with DC with LVDS and VGA. These connector types are not currently supported with DC. I'd like to add support but unfortunately don't have a system with LVDS or VGA available. In order not to cause regressions we should probably fallback to the non-DC driver for ASICs that support VGA and LVDS. These ASICs are: * Bonaire * Kabini * Kaveri * Mullins ASIC support can always be force enabled with amdgpu.dc=1 v2: Keep Hawaii on DC v3: Added Mullins to the list Cc: stable@vger.kernel.org Signed-off-by: Harry Wentland Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index b39192f..3d23d8b 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -2207,10 +2207,18 @@ bool amdgpu_device_asic_has_dc_support(enum amd_asic_type asic_type) switch (asic_type) { #if defined(CONFIG_DRM_AMD_DC) case CHIP_BONAIRE: - case CHIP_HAWAII: case CHIP_KAVERI: case CHIP_KABINI: case CHIP_MULLINS: + /* + * We have systems in the wild with these ASICs that require + * LVDS and VGA support which is not supported with DC. + * + * Fallback to the non-DC driver here by default so as not to + * cause regressions. + */ + return amdgpu_dc > 0; + case CHIP_HAWAII: case CHIP_CARRIZO: case CHIP_STONEY: case CHIP_POLARIS10: -- 2.7.4