FAILED: patch "[PATCH] usb: host: xhci-rcar: Don't reload firmware after the" failed to apply to 4.9-stable tree

The patch below does not apply to the 4.9-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]>.

thanks,

greg k-h

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

From 57f3ffdc11143f56f1314972fe86fe17a0dcde85 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <[email protected]>
Date: Fri, 27 Aug 2021 15:32:27 +0900
Subject: [PATCH] usb: host: xhci-rcar: Don't reload firmware after the
completion

According to the datasheet, "Upon the completion of FW Download, there is no need to write or reload FW.". Otherwise, it's possible to cause unexpected behaviors. So, adds such a condition.

index 1bc4fe7b8c75..9888ba7d85b6 100644
@@ -134,6 +134,13 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
 	const struct soc_device_attribute *attr;
 	const char *firmware_name;
 
+	/*
+	 * According to the datasheet, "Upon the completion of FW Download,
+	 * there is no need to write or reload FW".
+	 */
+	if (readl(regs + RCAR_USB3_DL_CTRL) & RCAR_USB3_DL_CTRL_FW_SUCCESS)
+		return 0;
+
 	attr = soc_device_match(rcar_quirks_match);
 	if (attr)
 		quirks = (uintptr_t)attr->data;