From 4693e852f19a1338a49e540fb99fe3b2898d8594 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Thu, 9 Feb 2023 09:00:02 -0500 Subject: [PATCH] drm/amdgpu: add S/G display parameter MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Some users have reported flickerng with S/G display. We've tried extensively to reproduce and debug the issue on a wide variety of platform configurations (DRAM bandwidth, etc.) and a variety of monitors, but so far have not been able to. We disabled S/G display on a number of platforms to address this but that leads to failure to pin framebuffers errors and blank displays when there is memory pressure or no displays at all on systems with limited carveout (e.g., Chromebooks). Add a option to disable this as a debugging option as a way for users to disable this, depending on their use case, and for us to help debug this further. v2: fix typo Reviewed-by: Harry Wentland Acked-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 + drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 11 +++++++++++ drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++ 3 files changed, 15 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index e3e2e6e..d148a1bd 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -243,6 +243,7 @@ extern int amdgpu_num_kcq; #define AMDGPU_VCNFW_LOG_SIZE (32 * 1024) extern int amdgpu_vcnfw_log; +extern int amdgpu_sg_display; #define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index cd4caaa..3fe277b 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -186,6 +186,7 @@ int amdgpu_num_kcq = -1; int amdgpu_smartshift_bias; int amdgpu_use_xgmi_p2p = 1; int amdgpu_vcnfw_log; +int amdgpu_sg_display = -1; /* auto */ static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work); @@ -932,6 +933,16 @@ MODULE_PARM_DESC(vcnfw_log, "Enable vcnfw log(0 = disable (default value), 1 = e module_param_named(vcnfw_log, amdgpu_vcnfw_log, int, 0444); /** + * DOC: sg_display (int) + * Disable S/G (scatter/gather) display (i.e., display from system memory). + * This option is only relevant on APUs. Set this option to 0 to disable + * S/G display if you experience flickering or other issues under memory + * pressure and report the issue. + */ +MODULE_PARM_DESC(sg_display, "S/G Display (-1 = auto (default), 0 = disable)"); +module_param_named(sg_display, amdgpu_sg_display, int, 0444); + +/** * DOC: smu_pptable_id (int) * Used to override pptable id. id = 0 use VBIOS pptable. * id > 0 use the soft pptable with specicfied id. diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 7845285..c1da9ac 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1523,6 +1523,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev) } 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) adev->mode_info.gpu_vm_support = true; -- 2.7.4