intel: Support debugging through AccelMethod

Ease debugging by allowing all acceleration or render acceleration to be
disabled through AccelMethod:

Option "AccelMethod" "off" -> disable all acceleration
Option "AccelMethod" "blt" -> disable render acceleration (only use BLT)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

6 files changed, 33 insertions, 7 deletions

diff --git a/man/intel.man b/man/intel.man
index 33ccb2dd..16db5211 100644
--- a/man/intel.man
+++ b/man/intel.man
@@ -128,6 +128,9 @@ Acceleration Architecture) is the mature backend that was introduced to support
 the GEM driver model. It is in the process of being superseded by \*qSNA\*q
 (Sandybridge's New Acceleration). Until that process is complete, the ability to
 choose which backend to use remains for backwards compatibility.
+In addition, there are a pair of sub-options to limit the acceleration for
+debuging use. Specify \*qoff\*q to disable all acceleration, or \*qblt\*q to
+disable render acceleration and only use the BLT engine.
 .IP
 Default: use UXA (render acceleration)
 .TP
diff --git a/src/intel_driver.c b/src/intel_driver.c
index 5a176dcb..5d3e1033 100644
--- a/src/intel_driver.c
+++ b/src/intel_driver.c
@@ -405,7 +405,8 @@ static Bool can_accelerate_blt(struct intel_screen_private *intel)
 	if (INTEL_INFO(intel)->gen == -1)
 		return FALSE;
 
-	if (xf86ReturnOptValBool(intel->Options, OPTION_ACCEL_DISABLE, FALSE)) {
+	if (xf86ReturnOptValBool(intel->Options, OPTION_ACCEL_DISABLE, FALSE) ||
+	    !intel_option_cast_string_to_bool(intel, OPTION_ACCEL_METHOD, TRUE)) {
 		xf86DrvMsg(intel->scrn->scrnIndex, X_CONFIG,
 			   "Disabling hardware acceleration.\n");
 		return FALSE;
diff --git a/src/intel_uxa.c b/src/intel_uxa.c
index 76a3146f..60ab3a64 100644
--- a/src/intel_uxa.c
+++ b/src/intel_uxa.c
@@ -1292,6 +1292,17 @@ intel_limits_init(intel_screen_private *intel)
 	}
 }
 
+static Bool intel_option_accel_blt(intel_screen_private *intel)
+{
+	const char *s;
+
+	s = xf86GetOptValString(intel->Options, OPTION_ACCEL_METHOD);
+	if (s == NULL)
+		return false;
+
+	return strcasecmp(s, "blt") == 0;
+}
+
 Bool intel_uxa_init(ScreenPtr screen)
 {
 	ScrnInfoPtr scrn = xf86ScreenToScrn(screen);
@@ -1338,7 +1349,8 @@ Bool intel_uxa_init(ScreenPtr screen)
 	intel->uxa_driver->done_copy = intel_uxa_done;
 
 	/* Composite */
-	if (IS_GEN2(intel)) {
+	if (intel_option_accel_blt(intel)) {
+	} else if (IS_GEN2(intel)) {
 		intel->uxa_driver->check_composite = i830_check_composite;
 		intel->uxa_driver->check_composite_target = i830_check_composite_target;
 		intel->uxa_driver->check_composite_texture = i830_check_composite_texture;
diff --git a/src/sna/sna.h b/src/sna/sna.h
index 8861fd9a..c7ebbd93 100644
--- a/src/sna/sna.h
+++ b/src/sna/sna.h
@@ -79,7 +79,6 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define DBG(x)
 #endif
 
-#define DEBUG_NO_RENDER 0
 #define DEBUG_NO_BLT 0
 
 #define DEBUG_FLUSH_BATCH 0
diff --git a/src/sna/sna_accel.c b/src/sna/sna_accel.c
index f59f153c..2c6347d6 100644
--- a/src/sna/sna_accel.c
+++ b/src/sna/sna_accel.c
@@ -29,6 +29,7 @@
 #include "config.h"
 #endif
 
+#include "intel_options.h"
 #include "sna.h"
 #include "sna_reg.h"
 #include "rop.h"
@@ -14208,6 +14209,17 @@ static bool sna_picture_init(ScreenPtr screen)
 	return true;
 }
 
+static bool sna_option_accel_blt(struct sna *sna)
+{
+	const char *s;
+
+	s = xf86GetOptValString(sna->Options, OPTION_ACCEL_METHOD);
+	if (s == NULL)
+		return false;
+
+	return strcasecmp(s, "blt") == 0;
+}
+
 bool sna_accel_init(ScreenPtr screen, struct sna *sna)
 {
 	const char *backend;
@@ -14286,8 +14298,7 @@ bool sna_accel_init(ScreenPtr screen, struct sna *sna)
 	sna->have_render = false;
 	no_render_init(sna);
 
-#if !DEBUG_NO_RENDER
-	if (sna->info->gen >= 0100) {
+	if (sna_option_accel_blt(sna) || sna->info->gen >= 0100) {
 	} else if (sna->info->gen >= 070) {
 		if ((sna->have_render = gen7_render_init(sna)))
 			backend = "IvyBridge";
@@ -14307,7 +14318,6 @@ bool sna_accel_init(ScreenPtr screen, struct sna *sna)
 		if ((sna->have_render = gen2_render_init(sna)))
 			backend = "gen2";
 	}
-#endif
 	DBG(("%s(backend=%s, have_render=%d)\n",
 	     __FUNCTION__, backend, sna->have_render));
 
diff --git a/src/sna/sna_driver.c b/src/sna/sna_driver.c
index 22770c79..ff0c776c 100644
--- a/src/sna/sna_driver.c
+++ b/src/sna/sna_driver.c
@@ -473,7 +473,8 @@ static Bool sna_pre_init(ScrnInfoPtr scrn, int flags)
 	intel_detect_chipset(scrn, sna->pEnt, sna->PciInfo);
 
 	kgem_init(&sna->kgem, fd, sna->PciInfo, sna->info->gen);
-	if (xf86ReturnOptValBool(sna->Options, OPTION_ACCEL_DISABLE, FALSE)) {
+	if (xf86ReturnOptValBool(sna->Options, OPTION_ACCEL_DISABLE, FALSE) ||
+	    !sna_option_cast_to_bool(sna, OPTION_ACCEL_METHOD, TRUE)) {
 		xf86DrvMsg(sna->scrn->scrnIndex, X_CONFIG,
 			   "Disabling hardware acceleration.\n");
 		sna->kgem.wedged = true;