Thread (1 message) 1 message, 1 author, 2017-05-23

Re: [PATCH 1/3] usb: host: ohci-platform: Add basic runtime PM support

From: Alan Stern <hidden>
Date: 2017-05-23 16:53:47
Also in: linux-omap

On Mon, 22 May 2017, Tony Lindgren wrote:
quoted hunk
This is needed in preparation of adding support for omap3 and
later OHCI. The runtime PM will only do something on platforms
that implement it.

Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Hans de Goede <redacted>
Cc: Rob Herring <redacted>
Cc: Roger Quadros <redacted>
Cc: Sebastian Reichel <sebastian.reichel-ZGY8ohtN/8pPYcu2f3hruQ@public.gmane.org>
Cc: Yoshihiro Shimoda <redacted>
Signed-off-by: Tony Lindgren <redacted>
---

Alan, do you have some better ideas for the ohci_platform_remove()
path below?

---
 drivers/usb/host/ohci-platform.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -24,6 +24,7 @@
 #include <linux/err.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/usb/ohci_pdriver.h>
 #include <linux/usb.h>
@@ -242,6 +243,8 @@ static int ohci_platform_probe(struct platform_device *dev)
 	}
 #endif
 
+	pm_runtime_set_active(&dev->dev);
+	pm_runtime_enable(&dev->dev);
 	if (pdata->power_on) {
 		err = pdata->power_on(dev);
 		if (err < 0)
@@ -271,6 +274,7 @@ static int ohci_platform_probe(struct platform_device *dev)
 	if (pdata->power_off)
 		pdata->power_off(dev);
 err_reset:
+	pm_runtime_disable(&dev->dev);
 	while (--rst >= 0)
 		reset_control_assert(priv->resets[rst]);
 err_put_clks:
@@ -290,7 +294,14 @@ static int ohci_platform_remove(struct platform_device *dev)
 	struct usb_hcd *hcd = platform_get_drvdata(dev);
 	struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
 	struct ohci_platform_priv *priv = hcd_to_ohci_priv(hcd);
-	int clk, rst;
+	int clk, rst, enabled;
+
+	enabled = pm_runtime_get_sync(&dev->dev);
+	if (enabled < 0) {
+		dev_warn(&dev->dev, "pm_runtime_get failed: %i\n",
+			 enabled);
+		pm_runtime_put_noidle(&dev->dev);
+	}
I wouldn't worry about checking the return value.  There's no 
particular reason for this call to fail, is there?
quoted hunk
 
 	usb_remove_hcd(hcd);
 
@@ -305,6 +316,10 @@ static int ohci_platform_remove(struct platform_device *dev)
 
 	usb_put_hcd(hcd);
 
+	if (enabled >= 0)
+		pm_runtime_put_sync(&dev->dev);
+	pm_runtime_disable(&dev->dev);
And here you could just do the put_sync, with no test.  If the get_sync
failed then this will probably fail too, but you won't be any worse off
for the attempt.

Alan Stern
+
 	if (pdata == &ohci_platform_defaults)
 		dev->dev.platform_data = NULL;
--
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