[Intel-gfx] [PATCH 2/8] drm/i915: Specify bsd rings through exec flag

[Rodrigo Vivi]

From: Zhipeng Gong <zhipeng.gong at intel.com>

On Broadwell GT3 we have 2 Video Command Streamers (VCS), but userspace
has no control when using VCS1 or VCS2. This patch introduces a mechanism
to avoid the default ping-pong mode and use one specific ring through
execution flag.

v2: fix whitespace (Rodrigo)

Signed-off-by: Zhipeng Gong <zhipeng.gong at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c | 19 +++++++++++++++++--
 drivers/gpu/drm/i915/intel_dp.c            |  3 +++
 include/uapi/drm/i915_drm.h                |  8 +++++++-
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index e1ed85a..d9081ec 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1273,8 +1273,23 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	else if ((args->flags & I915_EXEC_RING_MASK) == I915_EXEC_BSD) {
 		if (HAS_BSD2(dev)) {
 			int ring_id;
-			ring_id = gen8_dispatch_bsd_ring(dev, file);
-			ring = &dev_priv->ring[ring_id];
+
+			switch (args->flags & I915_EXEC_BSD_MASK) {
+			case I915_EXEC_BSD_DEFAULT:
+				ring_id = gen8_dispatch_bsd_ring(dev, file);
+				ring = &dev_priv->ring[ring_id];
+				break;
+			case I915_EXEC_BSD_RING1:
+				ring = &dev_priv->ring[VCS];
+				break;
+			case I915_EXEC_BSD_RING2:
+				ring = &dev_priv->ring[VCS2];
+				break;
+			default:
+				DRM_DEBUG("execbuf with unknown bsd ring: %d\n",
+					  (int)(args->flags & I915_EXEC_BSD_MASK));
+				return -EINVAL;
+			}
 		} else
 			ring = &dev_priv->ring[VCS];
 	} else
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index ceb528f..a8c9e47 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4802,6 +4802,9 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
 		if (HAS_PCH_SPLIT(dev)) {
 			if (!ibx_digital_port_connected(dev_priv, intel_dig_port))
 				goto mst_fail;
+		if (!intel_dp->output_reg)
+			goto mst_fail;
+
 		} else {
 			if (g4x_digital_port_connected(dev, intel_dig_port) != 1)
 				goto mst_fail;
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 2502622..fcb16bf 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -737,7 +737,13 @@ struct drm_i915_gem_execbuffer2 {
  */
 #define I915_EXEC_HANDLE_LUT		(1<<12)
 
-#define __I915_EXEC_UNKNOWN_FLAGS -(I915_EXEC_HANDLE_LUT<<1)
+/** Used for switching BSD rings on the platforms with two BSD rings */
+#define I915_EXEC_BSD_MASK		(3<<13)
+#define I915_EXEC_BSD_DEFAULT		(0<<13) /* default ping-pong mode */
+#define I915_EXEC_BSD_RING1		(1<<13)
+#define I915_EXEC_BSD_RING2		(2<<13)
+
+#define __I915_EXEC_UNKNOWN_FLAGS -(1<<15)
 
 #define I915_EXEC_CONTEXT_ID_MASK	(0xffffffff)
 #define i915_execbuffer2_set_context_id(eb2, context) \
-- 
1.9.3