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From: Douglas Anderson <dianders@chromium.org>
To: Minas Harutyunyan <hminas@synopsys.com>,
	Felipe Balbi <felipe.balbi@linux.intel.com>,
	heiko@sntech.de
Cc: Alan Stern <stern@rowland.harvard.edu>,
	Artur Petrosyan <Arthur.Petrosyan@synopsys.com>,
	amstan@chromium.org, linux-rockchip@lists.infradead.org,
	William Wu <william.wu@rock-chips.com>,
	linux-usb@vger.kernel.org, Stefan Wahren <stefan.wahren@i2se.com>,
	Randy Li <ayaka@soulik.info>,
	zyw@rock-chips.com, mka@chromium.org, ryandcase@chromium.org,
	Amelie Delaunay <amelie.delaunay@st.com>,
	jwerner@chromium.org, dinguyen@opensource.altera.com,
	Elaine Zhang <zhangqing@rock-chips.com>,
	Douglas Anderson <dianders@chromium.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 4/5] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled
Date: Wed, 17 Apr 2019 17:13:55 -0700
Message-ID: <20190418001356.124334-5-dianders@chromium.org> (raw)
Message-ID: <20190418001355.2Wyp2X9Macey8e5kJ20F1E0nWhHfezddJyCv0YVOojo@z> (raw)
In-Reply-To: <20190418001356.124334-1-dianders@chromium.org>

If the 'snps,need-phy-for-wake' is set in the device tree then:

- We know that we can wakeup, so call device_set_wakeup_capable().
  The USB core will use this knowledge to enable wakeup by default.
- We know that we should keep the PHY on during suspend if something
  on our root hub needs remote wakeup.  This requires the patch (USB:
  Export usb_wakeup_enabled_descendants()).  Note that we don't keep
  the PHY on at suspend time if it's not needed because it would be a
  power draw.

If we later find some users of dwc2 that can support wakeup without
keeping the PHY on we may want to add a way to call
device_set_wakeup_capable() without keeping the PHY on at suspend
time.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
---
For relevant prior discussion of this idea, see:

https://lkml.kernel.org/r/1436207224-21849-4-git-send-email-dianders@chromium.org

If I'm reading all the responses correctly folks were of the opinion
that this patch is still the right way to go.

Changes in v2:
- Rebased to mainline atop rk3288 remote wake quirk series.

 drivers/usb/dwc2/core.h     |  5 +++++
 drivers/usb/dwc2/platform.c | 43 +++++++++++++++++++++++++++++++++++--
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index f30748f4fe7e..a99fe7851352 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -861,6 +861,9 @@ struct dwc2_hregs_backup {
  * @hibernated:		True if core is hibernated
  * @reset_phy_on_wake:	Quirk saying that we should assert PHY reset on a
  *			remote wakeup.
+ * @phy_off_for_suspend: Status of whether we turned the PHY off at suspend.
+ * @need_phy_for_wake:	Quirk saying that we should keep the PHY on at
+ *			suspend if we need USB to wake us up.
  * @frame_number:       Frame number read from the core. For both device
  *			and host modes. The value ranges are from 0
  *			to HFNUM_MAX_FRNUM.
@@ -1049,6 +1052,8 @@ struct dwc2_hsotg {
 	unsigned int ll_hw_enabled:1;
 	unsigned int hibernated:1;
 	unsigned int reset_phy_on_wake:1;
+	unsigned int need_phy_for_wake:1;
+	unsigned int phy_off_for_suspend:1;
 	u16 frame_number;
 
 	struct phy *phy;
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 9b65b766e0b9..6f0271c5d163 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -47,7 +47,9 @@
 #include <linux/phy/phy.h>
 #include <linux/platform_data/s3c-hsotg.h>
 #include <linux/reset.h>
+#include <linux/usb.h>
 
+#include <linux/usb/hcd.h>
 #include <linux/usb/of.h>
 
 #include "core.h"
@@ -450,6 +452,10 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	if (retval)
 		goto error;
 
+	hsotg->need_phy_for_wake =
+		of_property_read_bool(dev->dev.of_node,
+				      "snps,need-phy-for-wake");
+
 	/*
 	 * Reset before dwc2_get_hwparams() then it could get power-on real
 	 * reset value form registers.
@@ -481,6 +487,14 @@ static int dwc2_driver_probe(struct platform_device *dev)
 		hsotg->gadget_enabled = 1;
 	}
 
+	/*
+	 * If we need PHY for wakeup we must be wakeup capable.
+	 * When we have a device that can wake without the PHY we
+	 * can adjust this condition.
+	 */
+	if (hsotg->need_phy_for_wake)
+		device_set_wakeup_capable(&dev->dev, true);
+
 	hsotg->reset_phy_on_wake =
 		of_property_read_bool(dev->dev.of_node,
 				      "snps,reset-phy-on-wake");
@@ -516,6 +530,28 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	return retval;
 }
 
+static bool __maybe_unused dwc2_can_poweroff_phy(struct dwc2_hsotg *dwc2)
+{
+	struct usb_device *root_hub = dwc2_hsotg_to_hcd(dwc2)->self.root_hub;
+
+	if (!dwc2->ll_hw_enabled)
+		return false;
+
+	/* If the controller isn't allowed to wakeup then we can power off. */
+	if (!device_may_wakeup(dwc2->dev))
+		return true;
+
+	/*
+	 * We don't want to power off the PHY if something under the
+	 * root hub has wakeup enabled.
+	 */
+	if (usb_wakeup_enabled_descendants(root_hub))
+		return false;
+
+	/* No reason to keep the PHY powered, so allow poweroff */
+	return true;
+}
+
 static int __maybe_unused dwc2_suspend(struct device *dev)
 {
 	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
@@ -524,8 +560,10 @@ static int __maybe_unused dwc2_suspend(struct device *dev)
 	if (dwc2_is_device_mode(dwc2))
 		dwc2_hsotg_suspend(dwc2);
 
-	if (dwc2->ll_hw_enabled)
+	if (dwc2_can_poweroff_phy(dwc2)) {
 		ret = __dwc2_lowlevel_hw_disable(dwc2);
+		dwc2->phy_off_for_suspend = true;
+	}
 
 	return ret;
 }
@@ -535,11 +573,12 @@ static int __maybe_unused dwc2_resume(struct device *dev)
 	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
 	int ret = 0;
 
-	if (dwc2->ll_hw_enabled) {
+	if (dwc2->phy_off_for_suspend && dwc2->ll_hw_enabled) {
 		ret = __dwc2_lowlevel_hw_enable(dwc2);
 		if (ret)
 			return ret;
 	}
+	dwc2->phy_off_for_suspend = false;
 
 	if (dwc2_is_device_mode(dwc2))
 		ret = dwc2_hsotg_resume(dwc2);
-- 
2.21.0.593.g511ec345e18-goog


  parent reply index

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-18  0:13 [PATCH v2 0/5] USB: dwc2: Allow wakeup from suspend; enable for rk3288-veyron Douglas Anderson
2019-04-18  0:13 ` [v2,1/5] usb: dwc2: bus suspend/resume for hosts with DWC2_POWER_DOWN_PARAM_NONE Doug Anderson
2019-04-18  0:13   ` [PATCH v2 1/5] " Douglas Anderson
2019-04-29  8:43   ` [v2,1/5] " Artur Petrosyan
2019-04-29  8:43     ` [PATCH v2 1/5] " Artur Petrosyan
2019-04-29 17:33     ` [v2,1/5] " Doug Anderson
2019-04-29 17:33       ` [PATCH v2 1/5] " Doug Anderson
2019-04-30  6:05       ` [v2,1/5] " Artur Petrosyan
2019-04-30  6:05         ` [PATCH v2 1/5] " Artur Petrosyan
2019-05-01  1:51         ` [v2,1/5] " Doug Anderson
2019-05-01  1:51           ` [PATCH v2 1/5] " Doug Anderson
2019-05-03  8:20           ` [v2,1/5] " Artur Petrosyan
2019-05-03  8:20             ` [PATCH v2 1/5] " Artur Petrosyan
2019-05-03 15:03             ` [v2,1/5] " Doug Anderson
2019-05-03 15:03               ` [PATCH v2 1/5] " Doug Anderson
2019-05-07  7:26               ` Artur Petrosyan
2019-05-01 23:58   ` [v2,1/5] " Doug Anderson
2019-05-01 23:58     ` [PATCH v2 1/5] " Doug Anderson
2019-05-03  8:25     ` [v2,1/5] " Artur Petrosyan
2019-05-03  8:25       ` [PATCH v2 1/5] " Artur Petrosyan
2019-05-03 15:07       ` [v2,1/5] " Doug Anderson
2019-05-03 15:07         ` [PATCH v2 1/5] " Doug Anderson
2019-05-07  7:05         ` Artur Petrosyan
2019-04-18  0:13 ` [v2,2/5] USB: Export usb_wakeup_enabled_descendants() Doug Anderson
2019-04-18  0:13   ` [PATCH v2 2/5] " Douglas Anderson
2019-04-18  0:13 ` [v2,3/5] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB Doug Anderson
2019-04-18  0:13   ` [PATCH v2 3/5] " Douglas Anderson
2019-04-25 12:40   ` [v2,3/5] " Felipe Balbi
2019-04-25 12:40     ` [PATCH v2 3/5] " Felipe Balbi
2019-04-25 18:09     ` [v2,3/5] " Doug Anderson
2019-04-25 18:09       ` [PATCH v2 3/5] " Doug Anderson
2019-04-25 19:58       ` [v2,3/5] " Doug Anderson
2019-04-25 19:58         ` [PATCH v2 3/5] " Doug Anderson
2019-05-02 18:36     ` [v2,3/5] " Doug Anderson
2019-05-02 18:36       ` [PATCH v2 3/5] " Doug Anderson
2019-04-30  1:23   ` [v2,3/5] " Rob Herring
2019-04-30  1:23     ` [PATCH v2 3/5] " Rob Herring
2019-04-30  5:25     ` [v2,3/5] " Doug Anderson
2019-04-30  5:25       ` [PATCH v2 3/5] " Doug Anderson
2019-04-18  0:13 ` Doug Anderson [this message]
2019-04-18  0:13   ` [PATCH v2 4/5] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled Douglas Anderson
2019-04-25 12:41   ` [v2,4/5] " Felipe Balbi
2019-04-25 12:41     ` [PATCH v2 4/5] " Felipe Balbi
2019-04-18  0:13 ` [v2,5/5] ARM: dts: rockchip: Allow wakeup from rk3288-veyron's dwc2 USB ports Doug Anderson
2019-04-18  0:13   ` [PATCH v2 5/5] " Douglas Anderson
2019-04-18 12:40 ` [PATCH v2 0/5] USB: dwc2: Allow wakeup from suspend; enable for rk3288-veyron Minas Harutyunyan
2019-04-18 15:54   ` Doug Anderson
2019-04-19 11:43     ` Artur Petrosyan
2019-04-19 16:44       ` Artur Petrosyan
2019-04-22 15:50         ` Artur Petrosyan

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