FAILED: patch "[PATCH] usb: dwc3: xilinx: make sure pipe clock is deselected in usb2" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x a48f744bef9ee74814a9eccb030b02223e48c76c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024121529-embellish-ruby-d51f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a48f744bef9ee74814a9eccb030b02223e48c76c Mon Sep 17 00:00:00 2001
From: Neal Frager <[email protected]>
Date: Mon, 2 Dec 2024 23:41:51 +0530
Subject: [PATCH] usb: dwc3: xilinx: make sure pipe clock is deselected in usb2
only mode

When the USB3 PHY is not defined in the Linux device tree, there could still be a case where there is a USB3 PHY active on the board and enabled by the first stage bootloader. If serdes clock is being used then the USB will fail to enumerate devices in 2.0 only mode.

To solve this, make sure that the PIPE clock is deselected whenever the USB3 PHY is not defined and guarantees that the USB2 only mode will work in all cases.

index e3738e1610db..a33a42ba0249 100644
@@ -121,8 +121,11 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
 	 * in use but the usb3-phy entry is missing from the device tree.
 	 * Therefore, skip these operations in this case.
 	 */
-	if (!priv_data->usb3_phy)
+	if (!priv_data->usb3_phy) {
+		/* Deselect the PIPE Clock Select bit in FPD PIPE Clock register */
+		writel(PIPE_CLK_DESELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK);
 		goto skip_usb3_phy;
+	}
 
 	crst = devm_reset_control_get_exclusive(dev, "usb_crst");
 	if (IS_ERR(crst)) {