From 57f3ffdc11143f56f1314972fe86fe17a0dcde85 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Fri, 27 Aug 2021 15:32:27 +0900
Subject: [PATCH] usb: host: xhci-rcar: Don't reload firmware after the
 completion
Git-commit: 57f3ffdc11143f56f1314972fe86fe17a0dcde85
References: git-fixes
Patch-mainline: v5.15-rc1

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.

Fixes: 4ac8918f3a73 ("usb: host: xhci-plat: add support for the R-Car H2 and M2 xHCI controllers")
Cc: stable@vger.kernel.org # v3.17+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20210827063227.81990-1-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/host/xhci-rcar.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/usb/host/xhci-rcar.c
+++ b/drivers/usb/host/xhci-rcar.c
@@ -122,6 +122,12 @@ static int xhci_rcar_download_firmware(s
 	int retval, index, j, time;
 	int timeout = 10000;
 	u32 data, val, temp;
+	/*
+	 * 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;
 
 	/* request R-Car USB3.0 firmware */
 	retval = request_firmware(&fw, priv->firmware_name, dev);