HSD #1509326948: fpga: altera-cvp: Recovery retry

If an incorrect bitstream is sent, there is a need
to retry the tear-down if it fails. We shall set
a maximum of 10 tries to recover the system from
a permanent failure.

Signed-off-by: Ang Tien Sung <tien.sung.ang@intel.com>

Author: tiensung

drivers/fpga/altera-cvp.c

@@ -66,6 +66,8 @@
 #define ALTERA_CVP_V1_SIZE	4
 #define ALTERA_CVP_V2_SIZE	4096
 
+/* Tear-down retry */
+#define CVP_TEARDOWN_MAX_RETRY 10
 /* Optional CvP config error status check for debugging */
 static bool altera_cvp_chkcfg;
 
@@ -315,6 +317,22 @@ static int altera_cvp_teardown(struct fpga_manager *mgr,
 	return ret;
 }
 
+static int altera_cvp_recovery(struct fpga_manager *mgr,
+			      struct fpga_image_info *info)
+{
+	int ret = 0, retry = 0;
+
+	for (retry = 0; retry < CVP_TEARDOWN_MAX_RETRY; retry++) {
+		ret = altera_cvp_teardown(mgr, info);
+		if (!ret)
+			break;
+		dev_warn(&mgr->dev,
+				 "%s: [%d] Tear-down failed. Retrying\n",
+				 __func__,
+				 retry);
+	}
+	return ret;
+}
 static int altera_cvp_write_init(struct fpga_manager *mgr,
 				 struct fpga_image_info *info,
 				 const char *buf, size_t count)
@@ -347,7 +365,7 @@ static int altera_cvp_write_init(struct fpga_manager *mgr,
 
 	if (val & VSE_CVP_STATUS_CFG_RDY) {
 		dev_warn(&mgr->dev, "CvP already started, tear down first\n");
-		ret = altera_cvp_teardown(mgr, info);
+		ret = altera_cvp_recovery(mgr, info);
 		if (ret)
 			return ret;
 	}
@@ -488,7 +506,7 @@ static int altera_cvp_write_complete(struct fpga_manager *mgr,
 	u32 mask, val;
 	int ret;
 
-	ret = altera_cvp_teardown(mgr, info);
+	ret = altera_cvp_recovery(mgr, info);
 	if (ret)
 		return ret;