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@xxxxxxxxxxxxxxx # v3.17+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
drivers/usb/host/xhci-rcar.c | 7 +++++++
1 file changed, 7 insertions(+)
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;
--
2.25.1
