From: Yaniv Gardi <ygardi@codeaurora.org>
Date: Thu, 10 Mar 2016 15:37:14 +0000 (+0200)
Subject: scsi: ufs: add retry for query descriptors
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a70e91b8bbaa3924d6598f9b4d1d468d2c88e6d3;p=linux-beck.git

scsi: ufs: add retry for query descriptors

Query commands have 100ms timeout and it may timeout if they are
issued in parallel to ongoing read/write SCSI commands, this change
adds the retry (max: 10) in case command timeouts.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 4eedb7fafa95..b429a57984a2 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1875,21 +1875,7 @@ static int ufshcd_query_attr_retry(struct ufs_hba *hba,
 	return ret;
 }
 
-/**
- * ufshcd_query_descriptor - API function for sending descriptor requests
- * hba: per-adapter instance
- * opcode: attribute opcode
- * idn: attribute idn to access
- * index: index field
- * selector: selector field
- * desc_buf: the buffer that contains the descriptor
- * buf_len: length parameter passed to the device
- *
- * Returns 0 for success, non-zero in case of failure.
- * The buf_len parameter will contain, on return, the length parameter
- * received on the response.
- */
-static int ufshcd_query_descriptor(struct ufs_hba *hba,
+static int __ufshcd_query_descriptor(struct ufs_hba *hba,
 			enum query_opcode opcode, enum desc_idn idn, u8 index,
 			u8 selector, u8 *desc_buf, int *buf_len)
 {
@@ -1953,6 +1939,39 @@ out:
 	return err;
 }
 
+/**
+ * ufshcd_query_descriptor_retry - API function for sending descriptor
+ * requests
+ * hba: per-adapter instance
+ * opcode: attribute opcode
+ * idn: attribute idn to access
+ * index: index field
+ * selector: selector field
+ * desc_buf: the buffer that contains the descriptor
+ * buf_len: length parameter passed to the device
+ *
+ * Returns 0 for success, non-zero in case of failure.
+ * The buf_len parameter will contain, on return, the length parameter
+ * received on the response.
+ */
+int ufshcd_query_descriptor_retry(struct ufs_hba *hba,
+			enum query_opcode opcode, enum desc_idn idn, u8 index,
+			u8 selector, u8 *desc_buf, int *buf_len)
+{
+	int err;
+	int retries;
+
+	for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
+		err = __ufshcd_query_descriptor(hba, opcode, idn, index,
+						selector, desc_buf, buf_len);
+		if (!err || err == -EINVAL)
+			break;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(ufshcd_query_descriptor_retry);
+
 /**
  * ufshcd_read_desc_param - read the specified descriptor parameter
  * @hba: Pointer to adapter instance
@@ -1995,9 +2014,9 @@ static int ufshcd_read_desc_param(struct ufs_hba *hba,
 			return -ENOMEM;
 	}
 
-	ret = ufshcd_query_descriptor(hba, UPIU_QUERY_OPCODE_READ_DESC,
-				      desc_id, desc_index, 0, desc_buf,
-				      &buff_len);
+	ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
+					desc_id, desc_index, 0, desc_buf,
+					&buff_len);
 
 	if (ret || (buff_len < ufs_query_desc_max_size[desc_id]) ||
 	    (desc_buf[QUERY_DESC_LENGTH_OFFSET] !=