[Intel-gfx] [PATCH v4 04/13] drm/i915/guc: Implement response handling in send_mmio()

[Michal Wajdeczko]

We're using data encoded in the status MMIO as return value from send
function, but GuC may also write more data in remaining MMIO regs.
Let's copy content of these registers to the buffer provided by caller.

v2: new line (Michel)
v3: updated commit message

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Oscar Mateo <oscar.mateo at intel.com>
Reviewed-by: Michel Thierry <michel.thierry at intel.com> #2
---
 drivers/gpu/drm/i915/intel_guc.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc.c b/drivers/gpu/drm/i915/intel_guc.c
index a533ff8..9ce01e5 100644
--- a/drivers/gpu/drm/i915/intel_guc.c
+++ b/drivers/gpu/drm/i915/intel_guc.c
@@ -368,11 +368,20 @@ 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);
+		goto out;
 	}
 
+	if (response_buf) {
+		int count = min(response_buf_size, guc->send_regs.count - 1);
+
+		for (i = 0; i < count; i++)
+			response_buf[i] = I915_READ(guc_send_reg(guc, i + 1));
+	}
+
+	/* Use data from the GuC response as our return value */
+	ret = INTEL_GUC_MSG_TO_DATA(status);
+
+out:
 	intel_uncore_forcewake_put(dev_priv, guc->send_regs.fw_domains);
 	mutex_unlock(&guc->send_mutex);
 
-- 
1.9.1