linux-kernel - [PATCH v7 08/14] scsi: ufs: add retries for hibern8 enter

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1454331770-29642-9-git-send-email-ygardi@codeaurora.org>
Date:	Mon,  1 Feb 2016 15:02:44 +0200
From:	Yaniv Gardi <ygardi@...eaurora.org>
To:	robherring2@...il.com, James.Bottomley@...senPartnership.com,
	pebolle@...cali.nl, hch@...radead.org
Cc:	linux-kernel@...r.kernel.org, linux-scsi@...r.kernel.org,
	linux-arm-msm@...r.kernel.org, santoshsy@...il.com,
	linux-scsi-owner@...r.kernel.org, subhashj@...eaurora.org,
	ygardi@...eaurora.org, gbroner@...eaurora.org,
	draviv@...eaurora.org, Vinayak Holikatti <vinholikatti@...il.com>,
	"James E.J. Bottomley" <JBottomley@...n.com>,
	"Martin K. Petersen" <martin.petersen@...cle.com>
Subject: [PATCH v7 08/14] scsi: ufs: add retries for hibern8 enter

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.

Reviewed-by: Gilad Broner <gbroner@...eaurora.org>
Reviewed-by: Dolev Raviv <draviv@...eaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@...eaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@...eaurora.org>

---
 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 4c0827f..1581d03 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -74,6 +74,9 @@
 /* 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
 
@@ -2387,13 +2390,32 @@ 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\n",
+			__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

-- 
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation