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From:   Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To:     hminas@synopsys.com, gregkh@linuxfoundation.org,
        p.zabel@pengutronix.de, johnyoun@synopsys.com,
        felipe.balbi@linux.intel.com
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-janitors@vger.kernel.org,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Subject: [PATCH] usb: dwc2: Fix some error handling paths
Date:   Fri,  5 May 2023 19:15:08 +0200
Message-Id: <c64537b5339342bd00f7c2152b8fc23792b9f95a.1683306479.git.christophe.jaillet@wanadoo.fr>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

dwc2_driver_probe() calls dwc2_lowlevel_hw_init() which deassert some reset
lines.
Should an error happen in dwc2_lowlevel_hw_init() after calling
reset_control_deassert() or in the probe after calling
dwc2_lowlevel_hw_init(), the reset lines remain deasserted.

Add some devm_add_action_or_reset() calls to re-assert the lines if needed.

Update the remove function accordingly.

This change is compile-tested only.

Fixes: 83f8da562f8b ("usb: dwc2: Add reset control to dwc2")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/usb/dwc2/platform.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 5aee284018c0..5cf025511cce 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -203,6 +203,11 @@ int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
 	return ret;
 }
 
+static void dwc2_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
 static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 {
 	int i, ret;
@@ -213,6 +218,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 				     "error getting reset control\n");
 
 	reset_control_deassert(hsotg->reset);
+	ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
+				       hsotg->reset);
+	if (ret)
+		return ret;
 
 	hsotg->reset_ecc = devm_reset_control_get_optional(hsotg->dev, "dwc2-ecc");
 	if (IS_ERR(hsotg->reset_ecc))
@@ -220,6 +229,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 				     "error getting reset control for ecc\n");
 
 	reset_control_deassert(hsotg->reset_ecc);
+	ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
+				       hsotg->reset_ecc);
+	if (ret)
+		return ret;
 
 	/*
 	 * Attempt to find a generic PHY, then look for an old style
@@ -339,9 +352,6 @@ static int dwc2_driver_remove(struct platform_device *dev)
 	if (hsotg->ll_hw_enabled)
 		dwc2_lowlevel_hw_disable(hsotg);
 
-	reset_control_assert(hsotg->reset);
-	reset_control_assert(hsotg->reset_ecc);
-
 	return 0;
 }
 
-- 
2.34.1