diff mbox

[v4,7/7] drm/i915/guc: change default to using GuC submission if possible

Message ID 1463150195-28805-8-git-send-email-david.s.gordon@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dave Gordon May 13, 2016, 2:36 p.m. UTC 
This patch simply changes the default value of "enable_guc_submission"
from 0 (never) to -1 (auto). This means that GuC submission will be
used if the platform has a GuC, the GuC supports the request submission
protocol, and any required GuC firmwware was successfully loaded. If any
of these conditions are not met, the driver will fall back to using
execlist mode.

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/i915_params.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Chris Wilson May 14, 2016, 8:32 a.m. UTC | #1 
On Fri, May 13, 2016 at 03:36:35PM +0100, Dave Gordon wrote:
> This patch simply changes the default value of "enable_guc_submission"
> from 0 (never) to -1 (auto). This means that GuC submission will be
> used if the platform has a GuC, the GuC supports the request submission
> protocol, and any required GuC firmwware was successfully loaded. If any
> of these conditions are not met, the driver will fall back to using
> execlist mode.

Why? This is the commit that people will bisect to, it should explain
why guc is preferred. At the moment, with the exception of reduced
context-switch overhead, I don't see any compelling advantage for
enabling guc, just lots of disadvantages.

Enabing a major feature like this, the commit should tell us the
advantages and disadvantages; and future roadmap (but really it should
be compelling in and of itself).
-Chris
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 6a5578c..573e787 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -55,7 +55,7 @@  struct i915_params i915 __read_mostly = {
 	.nuclear_pageflip = 0,
 	.edp_vswing = 0,
 	.enable_guc_loading = -1,
-	.enable_guc_submission = 0,
+	.enable_guc_submission = -1,
 	.guc_log_level = -1,
 	.enable_dp_mst = true,
 	.inject_load_failure = 0,
@@ -207,7 +207,7 @@  struct i915_params i915 __read_mostly = {
 module_param_named_unsafe(enable_guc_submission, i915.enable_guc_submission, int, 0400);
 MODULE_PARM_DESC(enable_guc_submission,
 		"Enable GuC submission "
-		"(-1=auto, 0=never [default], 1=if available, 2=required)");
+		"(-1=auto [default], 0=never, 1=if available, 2=required)");
 
 module_param_named(guc_log_level, i915.guc_log_level, int, 0400);
 MODULE_PARM_DESC(guc_log_level,