scsi: ufs: add retries to dme_peer get and set attribute

The dme_peer get/set attribute commands are prone to errors, therefore
we add three retries for the UIC command sending.  Error code returned
from ufshcd_send_uic_cmd() is checked, and unless it was successful or
the retries have finished, another command will be sent.

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Reviewed-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Lee Susman <lsusman@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 e374b79..4c0827f 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -68,6 +68,9 @@
 /* Task management command timeout */
 #define TM_CMD_TIMEOUT 100 /* msecs */
 
+/* maximum number of retries for a general UIC command  */
+#define UFS_UIC_COMMAND_RETRIES 3
+
 /* maximum number of link-startup retries */
 #define DME_LINKSTARTUP_RETRIES 3
 
@@ -2182,6 +2185,7 @@ int ufshcd_dme_set_attr(struct ufs_hba *hba, u32 attr_sel,
        };
        const char *set = action[!!peer];
        int ret;
+       int retries = UFS_UIC_COMMAND_RETRIES;
 
        uic_cmd.command = peer ?
                UIC_CMD_DME_PEER_SET : UIC_CMD_DME_SET;
@@ -2189,10 +2193,18 @@ int ufshcd_dme_set_attr(struct ufs_hba *hba, u32 attr_sel,
        uic_cmd.argument2 = UIC_ARG_ATTR_TYPE(attr_set);
        uic_cmd.argument3 = mib_val;
 
-       ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
-       if (ret)
-               dev_err(hba->dev, "%s: attr-id 0x%x val 0x%x error code %d\n",
-                       set, UIC_GET_ATTR_ID(attr_sel), mib_val, ret);
+       do {
+               /* for peer attributes we retry upon failure */
+               ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
+               if (ret)
+                       dev_dbg(hba->dev, "%s: attr-id 0x%x val 0x%x error code %d\n",
+                               set, UIC_GET_ATTR_ID(attr_sel), mib_val, ret);
+       } while (ret && peer && --retries);
+
+       if (!retries)
+               dev_err(hba->dev, "%s: attr-id 0x%x val 0x%x failed %d retries\n",
+                               set, UIC_GET_ATTR_ID(attr_sel), mib_val,
+                               retries);
 
        return ret;
 }
@@ -2217,6 +2229,7 @@ int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
        };
        const char *get = action[!!peer];
        int ret;
+       int retries = UFS_UIC_COMMAND_RETRIES;
        struct ufs_pa_layer_attr orig_pwr_info;
        struct ufs_pa_layer_attr temp_pwr_info;
        bool pwr_mode_change = false;
@@ -2247,14 +2260,19 @@ int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
                UIC_CMD_DME_PEER_GET : UIC_CMD_DME_GET;
        uic_cmd.argument1 = attr_sel;
 
-       ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
-       if (ret) {
-               dev_err(hba->dev, "%s: attr-id 0x%x error code %d\n",
-                       get, UIC_GET_ATTR_ID(attr_sel), ret);
-               goto out;
-       }
+       do {
+               /* for peer attributes we retry upon failure */
+               ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
+               if (ret)
+                       dev_dbg(hba->dev, "%s: attr-id 0x%x error code %d\n",
+                               get, UIC_GET_ATTR_ID(attr_sel), ret);
+       } while (ret && peer && --retries);
+
+       if (!retries)
+               dev_err(hba->dev, "%s: attr-id 0x%x failed %d retries\n",
+                               get, UIC_GET_ATTR_ID(attr_sel), retries);
 
-       if (mib_val)
+       if (mib_val && !ret)
                *mib_val = uic_cmd.argument3;
 
        if (peer && (hba->quirks & UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE)