[PATCHv5] drm/amdgpu: vi: disable ASPM on Intel Alder Lake based systems

From: Richard Gong
Date: Fri Apr 29 2022 - 12:08:34 EST


Active State Power Management (ASPM) feature is enabled since kernel 5.14.
There are some AMD Volcanic Islands (VI) GFX cards, such as the WX3200 and
RX640, that do not work with ASPM-enabled Intel Alder Lake based systems.
Using these GFX cards as video/display output, Intel Alder Lake based
systems will freeze after suspend/resume.

The issue was originally reported on one system (Dell Precision 3660 with
BIOS version 0.14.81), but was later confirmed to affect at least 4
pre-production Alder Lake based systems.

Add an extra check to disable ASPM on Intel Alder Lake based systems with
the problematic AMD Volcanic Islands GFX cards.

Fixes: 0064b0ce85bb ("drm/amd/pm: enable ASPM by default")
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1885
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Richard Gong <richard.gong@xxxxxxx>
---
v5: added vi to commit header and updated commit message
rolled back guard with the preprocessor as did in v2 to correct build
error on non-x86 systems
v4: s/CONFIG_X86_64/CONFIG_X86
enhanced check logic
v3: s/intel_core_aspm_chk/aspm_support_quirk_check
correct build error with W=1 option
v2: correct commit description
move the check from chip family to problematic platform
---
drivers/gpu/drm/amd/amdgpu/vi.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
index 039b90cdc3bc..45f0188c4273 100644
--- a/drivers/gpu/drm/amd/amdgpu/vi.c
+++ b/drivers/gpu/drm/amd/amdgpu/vi.c
@@ -81,6 +81,10 @@
#include "mxgpu_vi.h"
#include "amdgpu_dm.h"

+#if IS_ENABLED(CONFIG_X86)
+#include <asm/intel-family.h>
+#endif
+
#define ixPCIE_LC_L1_PM_SUBSTATE 0x100100C6
#define PCIE_LC_L1_PM_SUBSTATE__LC_L1_SUBSTATES_OVERRIDE_EN_MASK 0x00000001L
#define PCIE_LC_L1_PM_SUBSTATE__LC_PCI_PM_L1_2_OVERRIDE_MASK 0x00000002L
@@ -1134,13 +1138,24 @@ static void vi_enable_aspm(struct amdgpu_device *adev)
WREG32_PCIE(ixPCIE_LC_CNTL, data);
}

+static bool aspm_support_quirk_check(void)
+{
+#if IS_ENABLED(CONFIG_X86)
+ struct cpuinfo_x86 *c = &cpu_data(0);
+
+ return !(c->x86 == 6 && c->x86_model == INTEL_FAM6_ALDERLAKE);
+#else
+ return true;
+#endif
+}
+
static void vi_program_aspm(struct amdgpu_device *adev)
{
u32 data, data1, orig;
bool bL1SS = false;
bool bClkReqSupport = true;

- if (!amdgpu_device_should_use_aspm(adev))
+ if (!amdgpu_device_should_use_aspm(adev) || !aspm_support_quirk_check())
return;

if (adev->flags & AMD_IS_APU ||
--
2.25.1