Merge tag 'drm-intel-next-2018-09-21' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

Driver Changes:

- Bugzilla 107600: Fix stuttering video playback on MythTV on old hardware (Chris)
- Avoid black screen when using CSC coefficient matrix (Raviraj)
- Hammer PDs on Baytrail to make sure they reload (Chris)
- Capture some objects if unable to capture all, on error (Chris)
- Add W/A for 16 GB DIMMs on SKL+ (Mahesh)
- Only enable IPC for symmetric memory configurations on KBL+ (Mahesh)
- Assume pipe A to have maximum stride limits (Ville)
- Always update update OA contexts via context image (Tvrtko)
- Icelake enabling patches (Madhav, Dhinakaran)
- Add Icelake DMC firmware (Anusha)
- Fixes for CI found corner cases (Chris)
- Limit the backpressure for request allocation (Chris)
- Park GPU on module load so usage starts from known state (Chris)
- Flush tasklet when checking for idle (Chris)
- Use coherent write into the context image on BSW+ (Chris)
- Fix possible integer overflow for framebuffers that get aligned past 4GiB (Ville)
- Downgrade fence timeout from warn to notice and add debug hint (Chris)

- Fixes to multi function encoder code (Ville)
- Fix sprite plane check logic (Dan, Ville)
- PAGE_SIZE vs. I915_GTT_PAGE_SIZE fixes (Ville)
- Decode memory bandwidth and parameters for BXT and SKL+ (Mahesh)
- Overwrite BIOS set IPC value from KMS (Mahesh)
- Multiple pipe handling code cleanups/restructurings/optimizations (Ville)
- Spare low 4G address for non-48bit objects (Chris)
- Free context_setparam of struct_mutex (Chris)
- Delay updating ring register state on resume (Chris)
- Avoid unnecessarily copying overlay IOCTL parameters (Chris)
- Update GuC power domain states even without submission (Michal)
- Restore GuC preempt-context across S3/S4 (Chris)
- Add kernel selftest for rapid context switching (Chris)
- Keep runtime power management ref for live selftests (Chris)
- GEM code cleanups (Matt)

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180927095933.GA11458@jlahtine-desk.ger.corp.intel.com

1 files changed, 20 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 472939f5c18f..d0ef50bf930a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1677,9 +1677,26 @@ static int switch_context(struct i915_request *rq)
         GEM_BUG_ON(HAS_EXECLISTS(rq->i915));
 
         if (ppgtt) {
-                ret = load_pd_dir(rq, ppgtt);
-                if (ret)
-                        goto err;
+                int loops;
+
+                /*
+                 * Baytail takes a little more convincing that it really needs
+                 * to reload the PD between contexts. It is not just a little
+                 * longer, as adding more stalls after the load_pd_dir (i.e.
+                 * adding a long loop around flush_pd_dir) is not as effective
+                 * as reloading the PD umpteen times. 32 is derived from
+                 * experimentation (gem_exec_parallel/fds) and has no good
+                 * explanation.
+                 */
+                loops = 1;
+                if (engine->id == BCS && IS_VALLEYVIEW(engine->i915))
+                        loops = 32;
+
+                do {
+                        ret = load_pd_dir(rq, ppgtt);
+                        if (ret)
+                                goto err;
+                } while (--loops);
 
                 if (intel_engine_flag(engine) & ppgtt->pd_dirty_rings) {
                         unwind_mm = intel_engine_flag(engine);