Re: [PATCH v3 05/16] drm/i915: Disable the "binder"

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 1/16/2024 8:56 AM, Ville Syrjala wrote:
From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>

Now that the GGTT PTE updates go straight to GSMBASE (bypassing
GTTMMADR) there should be no more risk of system hangs? So the
"binder" (ie. update the PTEs via MI_UPDATE_GTT) is no longer
necessary, disable it.

My main worry with the MI_UPDATE_GTT are:
- only used on this one platform so very limited testing coverage
- async so more opprtunities to screw things up
- what happens if the engine hangs while we're waiting for MI_UPDATE_GTT
   to finish?
- requires working command submission, so even getting a working
   display now depends on a lot more extra components working correctly

TODO: MI_UPDATE_GTT might be interesting as an optimization
though, so perhaps someone should look into always using it
(assuming the GPU is alive and well)?

v2: Keep using MI_UPDATE_GTT on VM guests

Cc: Paz Zcharya <pazz@xxxxxxxxxxxx>
Cc: Nirmoy Das <nirmoy.das@xxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>

Reviewed-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>

---
  drivers/gpu/drm/i915/gt/intel_gtt.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index 86f73fe558ca..e83dabc56a14 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -24,7 +24,8 @@
  bool i915_ggtt_require_binder(struct drm_i915_private *i915)
  {
  	/* Wa_13010847436 & Wa_14019519902 */
-	return MEDIA_VER_FULL(i915) == IP_VER(13, 0);
+	return i915_run_as_guest() &&
+		MEDIA_VER_FULL(i915) == IP_VER(13, 0);
  }
static bool intel_ggtt_update_needs_vtd_wa(struct drm_i915_private *i915)



[Index of Archives]     [AMD Graphics]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux