[PATCH v2 11/17] scsi: ufs: add retry for query descriptors

From: Yaniv Gardi
Date: Mon Oct 26 2015 - 11:44:31 EST


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.

Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>

---
drivers/scsi/ufs/ufshcd.c | 55 +++++++++++++++++++++++++++++++----------------
1 file changed, 37 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 7558047..3c5b82a 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1902,21 +1902,7 @@ 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)
{
@@ -1981,6 +1967,39 @@ out:
}

/**
+ * 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
* @desc_id: descriptor idn value
@@ -2022,9 +2041,9 @@ 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] !=
--
1.8.5.2

--
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