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 stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
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
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@renesa... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c index 1bc4fe7b8c75..9888ba7d85b6 100644 --- a/drivers/usb/host/xhci-rcar.c +++ b/drivers/usb/host/xhci-rcar.c @@ -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;