[PATCH v4 08/15] scsi: ufs: add retries to dme_peer get and set attribute

From: Yaniv Gardi
Date: Sun Oct 25 2015 - 10:59:38 EST


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.

Signed-off-by: Lee Susman <lsusman@xxxxxxxxxxxxxx>
Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>

---
drivers/scsi/ufs/ufshcd.c | 40 +++++++++++++++++++++++++++++-----------
1 file changed, 29 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 8a04691..5005d12 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -70,6 +70,9 @@
/* 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

@@ -2185,6 +2188,7 @@ 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;
@@ -2192,10 +2196,18 @@ 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;
}
@@ -2220,6 +2232,7 @@ 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;
@@ -2250,14 +2263,19 @@ 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)
--
1.8.5.2

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