scsi: ufs-mediatek: Fix unbalanced clock on/off

MediaTek UFS clocks are separated to two parts and controlled by different
modules: ufs-mediatek and phy-ufs-mediatek.

If both Auto-Hibern8 and clk-gating feature are enabled, mphy power control
is not balanced thus unbalanced control also happens to the clocks probed
by phy-ufs-mediatek module.

Fix this issue by:

 - Promise usage of phy_power_on/off balanced

 - Remove phy_power_on/off control in suspend/resume vops since both can be
   handled in setup_clock vops only

Link: https://lore.kernel.org/r/20200601104646.15436-5-stanley.chu@mediatek.com
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 5f41b7b7db8fcc88a84620dba0432f21439e2c10..1cc7bea1468b0f13da20dd3f8e85a7827060aca3 100644 (file)
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -205,6 +205,23 @@ int ufs_mtk_wait_link_state(struct ufs_hba *hba, u32 state,
        return -ETIMEDOUT;
 }
 
+static void ufs_mtk_mphy_power_on(struct ufs_hba *hba, bool on)
+{
+       struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+       struct phy *mphy = host->mphy;
+
+       if (!mphy)
+               return;
+
+       if (on && !host->mphy_powered_on)
+               phy_power_on(mphy);
+       else if (!on && host->mphy_powered_on)
+               phy_power_off(mphy);
+       else
+               return;
+       host->mphy_powered_on = on;
+}
+
 /**
  * ufs_mtk_setup_clocks - enables/disable clocks
  * @hba: host controller instance
@@ -218,6 +235,7 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
 {
        struct ufs_mtk_host *host = ufshcd_get_variant(hba);
        int ret = 0;
+       bool clk_pwr_off = false;
 
        /*
         * In case ufs_mtk_init() is not yet done, simply ignore.
@@ -228,25 +246,29 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
                return 0;
 
        if (!on && status == PRE_CHANGE) {
-               if (!ufshcd_is_link_active(hba)) {
-                       ufs_mtk_setup_ref_clk(hba, on);
-                       ret = phy_power_off(host->mphy);
-               } else {
+               if (ufshcd_is_link_off(hba)) {
+                       clk_pwr_off = true;
+               } else if (ufshcd_is_link_hibern8(hba) ||
+                        (!ufshcd_can_hibern8_during_gating(hba) &&
+                        ufshcd_is_auto_hibern8_enabled(hba))) {
                        /*
-                        * Gate ref-clk if link state is in Hibern8
-                        * triggered by Auto-Hibern8.
+                        * Gate ref-clk and poweroff mphy if link state is in
+                        * OFF or Hibern8 by either Auto-Hibern8 or
+                        * ufshcd_link_state_transition().
                         */
-                       if (!ufshcd_can_hibern8_during_gating(hba) &&
-                           ufshcd_is_auto_hibern8_enabled(hba)) {
-                               ret = ufs_mtk_wait_link_state(hba,
-                                                             VS_LINK_HIBERN8,
-                                                             15);
-                               if (!ret)
-                                       ufs_mtk_setup_ref_clk(hba, on);
-                       }
+                       ret = ufs_mtk_wait_link_state(hba,
+                                                     VS_LINK_HIBERN8,
+                                                     15);
+                       if (!ret)
+                               clk_pwr_off = true;
+               }
+
+               if (clk_pwr_off) {
+                       ufs_mtk_setup_ref_clk(hba, on);
+                       ufs_mtk_mphy_power_on(hba, on);
                }
        } else if (on && status == POST_CHANGE) {
-               ret = phy_power_on(host->mphy);
+               ufs_mtk_mphy_power_on(hba, on);
                ufs_mtk_setup_ref_clk(hba, on);
        }
 
@@ -538,7 +560,6 @@ static void ufs_mtk_vreg_set_lpm(struct ufs_hba *hba, bool lpm)
 static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
        int err;
-       struct ufs_mtk_host *host = ufshcd_get_variant(hba);
 
        if (ufshcd_is_link_hibern8(hba)) {
                err = ufs_mtk_link_set_lpm(hba);
@@ -559,20 +580,13 @@ static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
                ufs_mtk_vreg_set_lpm(hba, true);
        }
 
-       if (!ufshcd_is_link_active(hba))
-               phy_power_off(host->mphy);
-
        return 0;
 }
 
 static int ufs_mtk_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
-       struct ufs_mtk_host *host = ufshcd_get_variant(hba);
        int err;
 
-       if (!ufshcd_is_link_active(hba))
-               phy_power_on(host->mphy);
-
        if (ufshcd_is_link_hibern8(hba)) {
                ufs_mtk_vreg_set_lpm(hba, false);
                err = ufs_mtk_link_set_hpm(hba);

diff --git a/drivers/scsi/ufs/ufs-mediatek.h b/drivers/scsi/ufs/ufs-mediatek.h
index fc42dcbfd8001ea54a7233e42afe841b0dc43a95..6052ec105ababf8c6f6fe4cfd0094a78be0337f7 100644 (file)
--- a/drivers/scsi/ufs/ufs-mediatek.h
+++ b/drivers/scsi/ufs/ufs-mediatek.h
@@ -91,6 +91,7 @@ enum {
 struct ufs_mtk_host {
        struct ufs_hba *hba;
        struct phy *mphy;
+       bool mphy_powered_on;
        bool unipro_lpm;
        bool ref_clk_enabled;
        u16 ref_clk_ungating_wait_us;