Re: [PATCH v6 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy

[Guenter Roeck]

Hi Frank,

On 06/16/2016 11:43 PM, Frank Wang wrote:

Hi Guenter,

On 2016/6/17 12:59, Guenter Roeck wrote:

On 06/16/2016 07:09 PM, Frank Wang wrote:

The newer SoCs (rk3366, rk3399) take a different usb-phy IP block
than rk3288 and before, and most of phy-related registers are also
different from the past, so a new phy driver is required necessarily.

Signed-off-by: Frank Wang <frank.w...@rock-chips.com>
Suggested-by: Guenter Roeck <li...@roeck-us.net>
Suggested-by: Doug Anderson <diand...@chromium.org>
Reviewed-by: Heiko Stuebner <he...@sntech.de>
Tested-by: Heiko Stuebner <he...@sntech.de>
---

[ ... ]

+
+static int rockchip_usb2phy_resume(struct phy *phy)
+{
+    struct rockchip_usb2phy_port *rport = phy_get_drvdata(phy);
+    struct rockchip_usb2phy *rphy = dev_get_drvdata(phy->dev.parent);
+    int ret;
+
+    dev_dbg(&rport->phy->dev, "port resume\n");
+
+    ret = clk_prepare_enable(rphy->clk480m);
+    if (ret)
+        return ret;
+

If suspend can be called multiple times, resume can be called
multiple times as well. Doesn't this cause a clock imbalance
if you call clk_prepare_enable() multiple times on resume,
but clk_disable_unprepare() only once on suspend ?

Well, what you said is reasonable, How does something like below?

@@ -307,6 +307,9 @@ static int rockchip_usb2phy_resume(struct phy *phy)

         dev_dbg(&rport->phy->dev, "port resume\n");

+       if (!rport->suspended)
+               return 0;
+
         ret = clk_prepare_enable(rphy->clk480m);
         if (ret)
                 return ret;
@@ -327,12 +330,16 @@ static int rockchip_usb2phy_suspend(struct phy *phy)

         dev_dbg(&rport->phy->dev, "port suspend\n");

+       if (rport->suspended)
+               return 0;
+
         ret = property_enable(rphy, &rport->port_cfg->phy_sus, true);
         if (ret)
                 return ret;

         rport->suspended = true;
         clk_disable_unprepare(rphy->clk480m);
+
         return 0;
  }

@@ -485,6 +492,7 @@ static int rockchip_usb2phy_host_port_init(struct 
rockchip_usb2phy *rphy,

         rport->port_id = USB2PHY_PORT_HOST;
         rport->port_cfg = &rphy->phy_cfg->port_cfgs[USB2PHY_PORT_HOST];
+       rport->suspended = true;

Why does it start in suspended mode ? That seems odd.

Guenter

         mutex_init(&rport->mutex);
         INIT_DELAYED_WORK(&rport->sm_work, rockchip_usb2phy_sm_work);