xf86-video-intel: src/intel_driver.c src/intel.h src/intel_shadow.c

[Chris Wilson]

 src/intel.h        |    1 +
 src/intel_driver.c |   22 +++++++++++++++++-----
 src/intel_shadow.c |    4 ++--
 3 files changed, 20 insertions(+), 7 deletions(-)

New commits:
commit 0bb135c40e5ac1bf7593ec1d68d2815cbf47aa25
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Tue Nov 23 22:27:38 2010 +0000

    Disable BLT for i830 and 845G
    
    This pair of chipsets seem broken beyond repair, specifically the
    erratum that causes the wrong PTE entry to be invalidated, so disable
    our incorrect attempts to use the BLT on those devices.
    
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

diff --git a/src/intel.h b/src/intel.h
index fa79a2f..ed21b1e 100644
--- a/src/intel.h
+++ b/src/intel.h
@@ -443,6 +443,7 @@ typedef struct intel_screen_private {
 
 	Bool use_pageflipping;
 	Bool force_fallback;
+	Bool can_blt;
 	Bool use_shadow;
 
 	/* Broken-out options. */
diff --git a/src/intel_driver.c b/src/intel_driver.c
index 926c7e3..e4aecfc 100644
--- a/src/intel_driver.c
+++ b/src/intel_driver.c
@@ -468,8 +468,21 @@ static void I830XvInit(ScrnInfoPtr scrn)
 		   intel->colorKey);
 }
 
-static Bool can_accelerate_2d(struct intel_screen_private *intel)
+static Bool can_accelerate_blt(struct intel_screen_private *intel)
 {
+	if (IS_I830(intel) || IS_845G(intel)) {
+		/* These pair of i8xx chipsets have a crippling erratum
+		 * that prevents the use of a PTE entry by the BLT
+		 * engine immediately following updating that
+		 * entry in the GATT.
+		 *
+		 * As the BLT is fundamental to our 2D acceleration,
+		 * and the workaround is lost in the midst of time,
+		 * fallback.
+		 */
+		return FALSE;
+	}
+
 	if (INTEL_INFO(intel)->gen >= 60) {
 		drm_i915_getparam_t gp;
 		int value;
@@ -592,9 +605,8 @@ static Bool I830PreInit(ScrnInfoPtr scrn, int flags)
 			intel->tiling = FALSE;
 	}
 
-	intel->use_shadow = FALSE;
-	if (!can_accelerate_2d(intel))
-		intel->use_shadow = TRUE;
+	intel->can_blt = can_accelerate_blt(intel);
+	intel->use_shadow = !intel->can_blt;
 
 	if (xf86IsOptionSet(intel->Options, OPTION_SHADOW)) {
 		intel->use_shadow =
@@ -606,7 +618,7 @@ static Bool I830PreInit(ScrnInfoPtr scrn, int flags)
 	if (intel->use_shadow) {
 		xf86DrvMsg(scrn->scrnIndex, X_CONFIG,
 			   "Shadow buffer enabled,"
-			   " GPU acceleration disabled.\n");
+			   " 2D GPU acceleration disabled.\n");
 	}
 
 	/* SwapBuffers delays to avoid tearing */
diff --git a/src/intel_shadow.c b/src/intel_shadow.c
index c12febc..b86530a 100644
--- a/src/intel_shadow.c
+++ b/src/intel_shadow.c
@@ -108,7 +108,7 @@ void intel_shadow_blt(intel_screen_private *intel)
 	int n;
 
 	/* Can we trust the BLT? Otherwise do an uncached mmecy. */
-	if (IS_GEN2(intel) || IS_GEN6(intel)) {
+	if (!intel->can_blt || IS_GEN2(intel)) {
 		intel_shadow_memcpy(intel);
 		return;
 	}
@@ -149,7 +149,7 @@ void intel_shadow_blt(intel_screen_private *intel)
 		if (bo == NULL)
 			return;
 
-		BEGIN_BATCH(8);
+		BEGIN_BATCH_BLT(8);
 		OUT_BATCH(blt);
 		OUT_BATCH(br13);
 		OUT_BATCH(box->y1 << 16 | box->x1);