[Intel-gfx] [PATCH v4 02/13] drm/i915/guc: Add support for data reporting in GuC responses

[Michal Wajdeczko]

GuC may return additional data in the response message.
Format and meaning of this data is action specific. We will
use this non-negative data as a new success return value.
Currently used actions don't return data that way yet.

v2: fix prohibited space after '~' (Michel)
    update commit message (Daniele)
v3: rebase

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Oscar Mateo <oscar.mateo at intel.com>
Cc: Michel Thierry <michel.thierry at intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Reviewed-by: Michel Thierry <michel.thierry at intel.com> #2
---
 drivers/gpu/drm/i915/intel_guc.c    |  3 +++
 drivers/gpu/drm/i915/intel_guc_ct.c | 14 ++++++++------
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc.c b/drivers/gpu/drm/i915/intel_guc.c
index 28075e6..77bf4e6 100644
--- a/drivers/gpu/drm/i915/intel_guc.c
+++ b/drivers/gpu/drm/i915/intel_guc.c
@@ -366,6 +366,9 @@ int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len)
 				 " ret=%d status=0x%08X response=0x%08X\n",
 				 action[0], ret, status,
 				 I915_READ(SOFT_SCRATCH(15)));
+	} else {
+		/* Use data from the GuC response as our return value */
+		ret = INTEL_GUC_MSG_TO_DATA(status);
 	}
 
 	intel_uncore_forcewake_put(dev_priv, guc->send_regs.fw_domains);
diff --git a/drivers/gpu/drm/i915/intel_guc_ct.c b/drivers/gpu/drm/i915/intel_guc_ct.c
index 1dafa7a..fa52259 100644
--- a/drivers/gpu/drm/i915/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/intel_guc_ct.c
@@ -400,7 +400,9 @@ static int ctch_send(struct intel_guc *guc,
 		return err;
 	if (!INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(*status))
 		return -EIO;
-	return 0;
+
+	/* Use data from the GuC status as our return value */
+	return INTEL_GUC_MSG_TO_DATA(*status);
 }
 
 /*
@@ -410,18 +412,18 @@ static int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len)
 {
 	struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
 	u32 status = ~0; /* undefined */
-	int err;
+	int ret;
 
 	mutex_lock(&guc->send_mutex);
 
-	err = ctch_send(guc, ctch, action, len, &status);
-	if (unlikely(err)) {
+	ret = ctch_send(guc, ctch, action, len, &status);
+	if (unlikely(ret < 0)) {
 		DRM_ERROR("CT: send action %#X failed; err=%d status=%#X\n",
-			  action[0], err, status);
+			  action[0], ret, status);
 	}
 
 	mutex_unlock(&guc->send_mutex);
-	return err;
+	return ret;
 }
 
 /**
-- 
1.9.1