From: William Wu <wulf@rock-chips.com>
Date: Wed, 4 Jan 2017 08:05:21 +0000 (+0800)
Subject: mfd: fusb302: avoid sending notifier to USB/DP during PM suspend
X-Git-Tag: firefly_0821_release~801
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=082f43af91698a82583053679ec0d0be89b36b2d;p=firefly-linux-kernel-4.4.55.git

mfd: fusb302: avoid sending notifier to USB/DP during PM suspend

When system enter PM suspend, it will use a flag genpd->suspend_
power_off to disable device power domain operations, and device
can't enable its power domain until complete PM resume, or rather,
until call pm_genpd_complete() to clear suspend_power_off flag.

In some case, e.g. plug in Type-C PD adapter during system suspend,
and then wakeup system, the fusb302 may send notifier to USB/DP
before USB/DP complete PM resume, this may cause USB/DP fail to
enable their power domain.

I don't find a way to make sure USB/DP PM resume, fortunately，
the PM framework provides a flag pm_freezing to indicate that
complete PM resume all of devices.

Change-Id: I5c9a467691956250c1fa99b7a83f5fe306c0730a
Signed-off-by: William Wu <wulf@rock-chips.com>
---

diff --git a/drivers/mfd/fusb302.c b/drivers/mfd/fusb302.c
index 6f07904718e4..3201a17fa53d 100644
--- a/drivers/mfd/fusb302.c
+++ b/drivers/mfd/fusb302.c
@@ -11,6 +11,7 @@
 
 #include <linux/delay.h>
 #include <linux/extcon.h>
+#include <linux/freezer.h>
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
@@ -248,6 +249,32 @@ static void platform_fusb_notify(struct fusb30x_chip *chip)
 			usb_ss = 1;
 		}
 
+		if (chip->notify.power_role == 0 &&
+		    chip->notify.is_pd_connected &&
+		    chip->pd_output_vol > 0 && chip->pd_output_cur > 0) {
+			extcon_set_state(chip->extcon, EXTCON_CHG_USB_FAST,
+					 true);
+			property.intval =
+				(chip->pd_output_cur << 15 |
+				 chip->pd_output_vol);
+			extcon_set_property(chip->extcon, EXTCON_CHG_USB_FAST,
+					    EXTCON_PROP_USB_TYPEC_POLARITY,
+					    property);
+			extcon_sync(chip->extcon, EXTCON_CHG_USB_FAST);
+		}
+
+#ifdef CONFIG_FREEZER
+		/*
+		 * If system enter PM suspend, we need to wait until
+		 * PM resume all of devices completion, then the flag
+		 * pm_freezing will be set to false, and we can send
+		 * notifier to USB/DP module safety, it make sure that
+		 * USB/DP can enable power domain successfully.
+		 */
+		while (pm_freezing)
+			usleep_range(10000, 11000);
+#endif
+
 		property.intval = flip;
 		extcon_set_property(chip->extcon, EXTCON_USB,
 				    EXTCON_PROP_USB_TYPEC_POLARITY, property);
@@ -269,18 +296,6 @@ static void platform_fusb_notify(struct fusb30x_chip *chip)
 		extcon_sync(chip->extcon, EXTCON_USB);
 		extcon_sync(chip->extcon, EXTCON_USB_HOST);
 		extcon_sync(chip->extcon, EXTCON_DISP_DP);
-		if (chip->notify.power_role == 0 &&
-		    chip->notify.is_pd_connected &&
-		    chip->pd_output_vol > 0 && chip->pd_output_cur > 0) {
-			extcon_set_state(chip->extcon, EXTCON_CHG_USB_FAST, true);
-			property.intval =
-				(chip->pd_output_cur << 15 |
-				 chip->pd_output_vol);
-			extcon_set_property(chip->extcon, EXTCON_CHG_USB_FAST,
-					    EXTCON_PROP_USB_TYPEC_POLARITY,
-					    property);
-			extcon_sync(chip->extcon, EXTCON_CHG_USB_FAST);
-		}
 	}
 }