[PATCH v3 14/14] usb: dwc2: Add exit partial power down before removing driver

From: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
To: Felipe Balbi <balbi@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: John Youn <John.Youn@synopsys.com>,
	Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Subject: [PATCH v3 14/14] usb: dwc2: Add exit partial power down before removing driver
Date: Thu, 08 Apr 2021 13:46:14 +0400	[thread overview]
Message-ID: <20210408094615.8AE35A0094@mailhost.synopsys.com> (raw)
In-Reply-To: <cover.1617782102.git.Arthur.Petrosyan@synopsys.com>

When dwc2 core is in partial power down mode
loading driver again causes driver fail. Because in
that mode registers are not accessible.

Added a flow of exiting the partial power down mode
to avoid the driver reload failure.

Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
---
 Changes in v3:
 - None
 Changes in v2:
 - None

 drivers/usb/dwc2/platform.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 5f18acac7406..b28b8cd45799 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -316,6 +316,15 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 static int dwc2_driver_remove(struct platform_device *dev)
 {
 	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
+	int ret = 0;
+
+	/* Exit Partial Power Down when driver is removed. */
+	if (hsotg->in_ppd) {
+		ret = dwc2_exit_partial_power_down(hsotg, 0, true);
+		if (ret)
+			dev_err(hsotg->dev,
+				"exit partial_power_down failed\n");
+	}
 
 	dwc2_debugfs_exit(hsotg);
 	if (hsotg->hcd_enabled)
@@ -334,7 +343,7 @@ static int dwc2_driver_remove(struct platform_device *dev)
 	reset_control_assert(hsotg->reset);
 	reset_control_assert(hsotg->reset_ecc);
 
-	return 0;
+	return ret;
 }
 
 /**
-- 
2.25.1

