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From:   Can Guo <cang@codeaurora.org>
To:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, ziqichen@codeaurora.org,
        rnayak@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com, saravanak@google.com, salyzyn@google.com,
        cang@codeaurora.org
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        Bart Van Assche <bvanassche@acm.org>,
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] scsi: ufs: Don't disable core_clk_unipro if the link is active
Date:   Mon, 23 Nov 2020 21:05:08 -0800
Message-Id: <1606194312-25378-1-git-send-email-cang@codeaurora.org>
Precedence: bulk

If we want to disable clocks but still keep the link active, both ref_clk
and core_clk_unipro should be skipped.

Signed-off-by: Can Guo <cang@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a7857f6..69c2e91 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -222,7 +222,7 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
 static void ufshcd_hba_exit(struct ufs_hba *hba);
 static int ufshcd_probe_hba(struct ufs_hba *hba, bool async);
 static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
-				 bool skip_ref_clk);
+				 bool keep_link_active);
 static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on);
 static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
 static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba);
@@ -1710,7 +1710,6 @@ static void ufshcd_gate_work(struct work_struct *work)
 	if (!ufshcd_is_link_active(hba))
 		ufshcd_setup_clocks(hba, false);
 	else
-		/* If link is active, device ref_clk can't be switched off */
 		__ufshcd_setup_clocks(hba, false, true);
 
 	/*
@@ -7991,7 +7990,7 @@ static int ufshcd_init_hba_vreg(struct ufs_hba *hba)
 }
 
 static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
-					bool skip_ref_clk)
+					bool keep_link_active)
 {
 	int ret = 0;
 	struct ufs_clk_info *clki;
@@ -8009,7 +8008,13 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 
 	list_for_each_entry(clki, head, list) {
 		if (!IS_ERR_OR_NULL(clki->clk)) {
-			if (skip_ref_clk && !strcmp(clki->name, "ref_clk"))
+			/*
+			 * To keep link active, ref_clk and core_clk_unipro
+			 * should be kept ON.
+			 */
+			if (keep_link_active &&
+			    (!strcmp(clki->name, "ref_clk") ||
+			     !strcmp(clki->name, "core_clk_unipro")))
 				continue;
 
 			clk_state_changed = on ^ clki->enabled;
@@ -8580,7 +8585,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (!ufshcd_is_link_active(hba))
 		ufshcd_setup_clocks(hba, false);
 	else
-		/* If link is active, device ref_clk can't be switched off */
 		__ufshcd_setup_clocks(hba, false, true);
 
 	if (ufshcd_is_clkgating_allowed(hba)) {
-- 
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