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authorNathan Schulte <nmschulte@gmail.com>2016-03-15 10:14:05 -0500
committerDaniel Vetter <daniel.vetter@ffwll.ch>2016-03-16 16:40:50 +0100
commit7cc96139d9e3f627bd18e5ee6a5e4e305369865b (patch)
tree4444d6193998d3f6bef72ba0a59b9b96c601279e
parent117897f42c87c11a3a8315507d38cbd99ea46fda (diff)
downloadlinux-7cc96139d9e3f627bd18e5ee6a5e4e305369865b.tar.bz2
drm/i915: add module param "enable_dp_mst"
Adds an (unsafe; auto-kernel-tainting) boolean module parameter to the i915 drm driver: "enable_dp_mst", which is enabled by default. Disabling the parameter forces newly connected DisplayPort sinks to report as not supporting multi-stream transport (MST), thus "forcing" the use of single-stream transport (SST). v2: rename parameter to conform to style v3: add signoff Signed-off-by: Nathan Schulte <nmschulte@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1458054845-5837-1-git-send-email-nmschulte@gmail.com
-rw-r--r--drivers/gpu/drm/i915/i915_params.c5
-rw-r--r--drivers/gpu/drm/i915/i915_params.h1
-rw-r--r--drivers/gpu/drm/i915/intel_dp.c3
3 files changed, 9 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 278c9c40c2e0..97691f1f679c 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -56,6 +56,7 @@ struct i915_params i915 __read_mostly = {
.edp_vswing = 0,
.enable_guc_submission = false,
.guc_log_level = -1,
+ .enable_dp_mst = true,
};
module_param_named(modeset, i915.modeset, int, 0400);
@@ -201,3 +202,7 @@ MODULE_PARM_DESC(enable_guc_submission, "Enable GuC submission (default:false)")
module_param_named(guc_log_level, i915.guc_log_level, int, 0400);
MODULE_PARM_DESC(guc_log_level,
"GuC firmware logging level (-1:disabled (default), 0-3:enabled)");
+
+module_param_named_unsafe(enable_dp_mst, i915.enable_dp_mst, bool, 0600);
+MODULE_PARM_DESC(enable_dp_mst,
+ "Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index bd5026b15d3e..87153b0199cd 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -59,6 +59,7 @@ struct i915_params {
bool enable_guc_submission;
bool verbose_state_checks;
bool nuclear_pageflip;
+ bool enable_dp_mst;
};
extern struct i915_params i915 __read_mostly;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 0e326e776e8f..ba2d0242d532 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3882,6 +3882,9 @@ intel_dp_probe_mst(struct intel_dp *intel_dp)
{
u8 buf[1];
+ if (!i915.enable_dp_mst)
+ return false;
+
if (!intel_dp->can_mst)
return false;