drm/i916: add "auto" pipe CRC source

On gmch platforms the normal pipe source CRC registers don't work for
DP and TV encoders. And on newer platforms the single pipe CRC has
been replaced by a set of CRC at different stages in the platform.

Now most of our userspace tests don't care one bit about the exact
CRC, they simply want something that reflects any changes on the
screen. Hence add a new auto target for platform agnostic tests to
use.

v2: Pass back the adjusted source so that it can be shown in debugfs.

v3: I seem to be unable to get a stable CRC for DP ports. So let's
just disable them for now when using the auto mode. Note that
testcases need to be restructured so that they can dynamically skip
connectors. They also first need to set up the desired mode
configuration, since otherwise the auto mode won't do the right thing.

v4: Don't leak the modeset mutex on error paths.

v5: Spelling fix for the i9xx auto_source function.

Cc: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -1936,6 +1936,7 @@ static const char * const pipe_crc_sources[] = {
 	"DP-B",
 	"DP-C",
 	"DP-D",
+	"auto",
 };
 
 static const char *pipe_crc_source_name(enum intel_pipe_crc_source source)
@@ -1964,10 +1965,13 @@ static int display_crc_ctl_open(struct inode *inode, struct file *file)
 	return single_open(file, display_crc_ctl_show, dev);
 }
 
-static int i8xx_pipe_crc_ctl_reg(enum intel_pipe_crc_source source,
+static int i8xx_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
 				 uint32_t *val)
 {
-	switch (source) {
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
+		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
+
+	switch (*source) {
 	case INTEL_PIPE_CRC_SOURCE_PIPE:
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_INCLUDE_BORDER_I8XX;
 		break;
@@ -1981,10 +1985,54 @@ static int i8xx_pipe_crc_ctl_reg(enum intel_pipe_crc_source source,
 	return 0;
 }
 
-static int vlv_pipe_crc_ctl_reg(enum intel_pipe_crc_source source,
+static int i9xx_pipe_crc_auto_source(struct drm_device *dev, enum pipe pipe,
+				     enum intel_pipe_crc_source *source)
+{
+	struct intel_encoder *encoder;
+	struct intel_crtc *crtc;
+	int ret = 0;
+
+	*source = INTEL_PIPE_CRC_SOURCE_PIPE;
+
+	mutex_lock(&dev->mode_config.mutex);
+	list_for_each_entry(encoder, &dev->mode_config.encoder_list,
+			    base.head) {
+		if (!encoder->base.crtc)
+			continue;
+
+		crtc = to_intel_crtc(encoder->base.crtc);
+
+		if (crtc->pipe != pipe)
+			continue;
+
+		switch (encoder->type) {
+		case INTEL_OUTPUT_TVOUT:
+			*source = INTEL_PIPE_CRC_SOURCE_TV;
+			break;
+		case INTEL_OUTPUT_DISPLAYPORT:
+		case INTEL_OUTPUT_EDP:
+			/* We can't get stable CRCs for DP ports somehow. */
+			ret = -ENODEV;
+			break;
+		}
+	}
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return ret;
+}
+
+static int vlv_pipe_crc_ctl_reg(struct drm_device *dev,
+				enum pipe pipe,
+				enum intel_pipe_crc_source *source,
 				uint32_t *val)
 {
-	switch (source) {
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
+		int ret = i9xx_pipe_crc_auto_source(dev, pipe, source);
+		if (ret)
+			return ret;
+	}
+
+	switch (*source) {
 	case INTEL_PIPE_CRC_SOURCE_PIPE:
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_VLV;
 		break;
@@ -2005,10 +2053,17 @@ static int vlv_pipe_crc_ctl_reg(enum intel_pipe_crc_source source,
 }
 
 static int i9xx_pipe_crc_ctl_reg(struct drm_device *dev,
-				 enum intel_pipe_crc_source source,
+				 enum pipe pipe,
+				 enum intel_pipe_crc_source *source,
 				 uint32_t *val)
 {
-	switch (source) {
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO) {
+		int ret = i9xx_pipe_crc_auto_source(dev, pipe, source);
+		if (ret)
+			return ret;
+	}
+
+	switch (*source) {
 	case INTEL_PIPE_CRC_SOURCE_PIPE:
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PIPE_I9XX;
 		break;
@@ -2042,10 +2097,13 @@ static int i9xx_pipe_crc_ctl_reg(struct drm_device *dev,
 	return 0;
 }
 
-static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source source,
+static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
 				uint32_t *val)
 {
-	switch (source) {
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
+		*source = INTEL_PIPE_CRC_SOURCE_PIPE;
+
+	switch (*source) {
 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_ILK;
 		break;
@@ -2065,10 +2123,13 @@ static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source source,
 	return 0;
 }
 
-static int ivb_pipe_crc_ctl_reg(enum intel_pipe_crc_source source,
+static int ivb_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
 				uint32_t *val)
 {
-	switch (source) {
+	if (*source == INTEL_PIPE_CRC_SOURCE_AUTO)
+		*source = INTEL_PIPE_CRC_SOURCE_PF;
+
+	switch (*source) {
 	case INTEL_PIPE_CRC_SOURCE_PLANE1:
 		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PRIMARY_IVB;
 		break;
@@ -2104,15 +2165,15 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 		return -EINVAL;
 
 	if (IS_GEN2(dev))
-		ret = i8xx_pipe_crc_ctl_reg(source, &val);
+		ret = i8xx_pipe_crc_ctl_reg(&source, &val);
 	else if (INTEL_INFO(dev)->gen < 5)
-		ret = i9xx_pipe_crc_ctl_reg(dev, source, &val);
+		ret = i9xx_pipe_crc_ctl_reg(dev, pipe, &source, &val);
 	else if (IS_VALLEYVIEW(dev))
-		ret = vlv_pipe_crc_ctl_reg(source, &val);
+		ret = vlv_pipe_crc_ctl_reg(dev,pipe, &source, &val);
 	else if (IS_GEN5(dev) || IS_GEN6(dev))
-		ret = ilk_pipe_crc_ctl_reg(source, &val);
+		ret = ilk_pipe_crc_ctl_reg(&source, &val);
 	else
-		ret = ivb_pipe_crc_ctl_reg(source, &val);
+		ret = ivb_pipe_crc_ctl_reg(&source, &val);
 
 	if (ret != 0)
 		return ret;

drivers/gpu/drm/i915/i915_drv.h

@@ -1251,6 +1251,7 @@ enum intel_pipe_crc_source {
 	INTEL_PIPE_CRC_SOURCE_DP_B,
 	INTEL_PIPE_CRC_SOURCE_DP_C,
 	INTEL_PIPE_CRC_SOURCE_DP_D,
+	INTEL_PIPE_CRC_SOURCE_AUTO,
 	INTEL_PIPE_CRC_SOURCE_MAX,
 };