[PATCH v1 09/15] scsi: ufs: add retries for hibern8 enter

From: Yaniv Gardi
Date: Fri Aug 21 2015 - 18:10:48 EST


If hibern8 enter command fails then UFS link state may be unknown which
may result into timeout of all the commands issued after failure.

This change does 2 things (for pre-defined number of retry counts) after
hibern8 enter failure:
1. Recovers the UFS link to active state
2. If link is recovered to active state, tries to put the UFS link in
hibern8 enter again until retry count expires.

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

---
drivers/scsi/ufs/ufshcd.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a146587..6d47e9e 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -75,6 +75,9 @@
/* maximum number of link-startup retries */
#define DME_LINKSTARTUP_RETRIES 3

+/* Maximum retries for Hibern8 enter */
+#define UIC_HIBERN8_ENTER_RETRIES 3
+
/* maximum number of reset retries before giving up */
#define MAX_HOST_RESET_RETRIES 5

@@ -2389,13 +2392,32 @@ out:
return ret;
}

-static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
+static int __ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
{
+ int ret;
struct uic_command uic_cmd = {0};

uic_cmd.command = UIC_CMD_DME_HIBER_ENTER;
+ ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
+
+ if (ret)
+ dev_err(hba->dev, "%s: hibern8 enter failed. ret = %d",
+ __func__, ret);
+
+ return ret;
+}
+
+static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
+{
+ int ret = 0, retries;

- return ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
+ for (retries = UIC_HIBERN8_ENTER_RETRIES; retries > 0; retries--) {
+ ret = __ufshcd_uic_hibern8_enter(hba);
+ if (!ret || ret == -ENOLINK)
+ goto out;
+ }
+out:
+ return ret;
}

static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
--
1.8.5.2

--
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