Am 24.01.23 um 16:13 schrieb Alex Deucher:
Add a module parameter to force sg (scatter/gather) display
on APUs. Normally we allow displays in both VRAM and GTT,
but this option forces displays into GTT so we can explicitly
test more scenarios with GTT.
We tried to avoid that very hard the last time the idea came up.
Generally I don't think that this is something end users should mess with.
It's certainly useful for internal testing, but I think educating
everybody how to change a define before compiling the driver should be
the better approach.
Regards,
Christian.
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++
drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 12 ++++++++++++
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 4 ++++
3 files changed, 18 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 872450a3a164..73d0a0807138 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -244,6 +244,8 @@ extern int amdgpu_num_kcq;
#define AMDGPU_VCNFW_LOG_SIZE (32 * 1024)
extern int amdgpu_vcnfw_log;
+extern int amdgpu_force_sg_display;
+
#define AMDGPU_VM_MAX_NUM_CTX 4096
#define AMDGPU_SG_THRESHOLD (256*1024*1024)
#define AMDGPU_DEFAULT_GTT_SIZE_MB 3072ULL /* 3GB by default */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index a75dba2caeca..bc0eaf2330f2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -942,6 +942,18 @@ MODULE_PARM_DESC(smu_pptable_id,
"specify pptable id to be used (-1 = auto(default) value, 0 = use pptable from vbios, > 0 = soft pptable id)");
module_param_named(smu_pptable_id, amdgpu_smu_pptable_id, int, 0444);
+/**
+ * DOC: force_sg_display (int)
+ * Force display buffers into GTT (scatter/gather) memory for APUs.
+ * This is used to force GTT only for displays rather than displaying from
+ * either VRAM (carve out) or GTT.
+ *
+ * Defaults to 0, or disabled.
+ */
+int amdgpu_force_sg_display;
+MODULE_PARM_DESC(force_sg_display, "Force S/G display (0 = off (default), 1 = force display to use GTT) ");
+module_param_named(force_sg_display, amdgpu_force_sg_display, int, 0444);
+
/* These devices are not supported by amdgpu.
* They are supported by the mach64, r128, radeon drivers
*/
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 2d237f3d3a2e..78dc5d63a6dd 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -1515,6 +1515,10 @@ uint32_t amdgpu_bo_get_preferred_domain(struct amdgpu_device *adev,
if (adev->gmc.real_vram_size <= AMDGPU_SG_THRESHOLD)
domain = AMDGPU_GEM_DOMAIN_GTT;
}
+ if (amdgpu_force_sg_display &&
+ (adev->asic_type >= CHIP_CARRIZO) &&
+ (adev->flags & AMD_IS_APU))
+ domain = AMDGPU_GEM_DOMAIN_GTT;
return domain;
}
