[PATCH 5.4 61/86] usb: gadget: aspeed: fix stop dma register setting.

[Greg Kroah-Hartman]

From: Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>

commit 4e0dcf62ab4cf917d0cbe751b8bf229a065248d4 upstream.

The vhub engine has two dma mode, one is descriptor list, another
is single stage DMA. Each mode has different stop register setting.
Descriptor list operation (bit2) : 0 disable reset, 1: enable reset
Single mode operation (bit0) : 0 : disable, 1: enable

Fixes: 7ecca2a4080c ("usb/gadget: Add driver for Aspeed SoC virtual hub")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Acked-by: Felipe Balbi <balbi@xxxxxxxxxx>
Acked-by: Joel Stanley <joel@xxxxxxxxx>
Signed-off-by: Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210108081238.10199-2-ryan_chen@xxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/gadget/udc/aspeed-vhub/epn.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/usb/gadget/udc/aspeed-vhub/epn.c
+++ b/drivers/usb/gadget/udc/aspeed-vhub/epn.c
@@ -420,7 +420,10 @@ static void ast_vhub_stop_active_req(str
 	u32 state, reg, loops;
 
 	/* Stop DMA activity */
-	writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	if (ep->epn.desc_mode)
+		writel(VHUB_EP_DMA_CTRL_RESET, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
+	else
+		writel(0, ep->epn.regs + AST_VHUB_EP_DMA_CTLSTAT);
 
 	/* Wait for it to complete */
 	for (loops = 0; loops < 1000; loops++) {