[nrf fromtree] drivers: udc_dwc2: Allocate multiple of bMaxPacketSize0

Control OUT buffers must be multiple of bMaxPacketSize0 in Buffer DMA
mode. While the transfer can be configured to smaller values, DMA will
write data past the buffer (and transfer size counter will underflow) if
the packet on the bus is larger or if there are multiple back-to-back
SETUP packets.

Signed-off-by: Tomasz Moń <[email protected]>
(cherry picked from commit a61afc8)
(cherry picked from commit 5ee4d80)

Author: tmon-nordic

drivers/usb/udc/udc_dwc2.c

@@ -666,8 +666,7 @@ static void dwc2_prep_rx(const struct device *dev, struct net_buf *buf,
 	doeptsiz = usb_dwc2_set_doeptsizn_pktcnt(pktcnt) |
 		   usb_dwc2_set_doeptsizn_xfersize(xfersize);
 	if (cfg->addr == USB_CONTROL_EP_OUT) {
-		/* Use 1 to allow 8 byte long buffers for SETUP data */
-		doeptsiz |= (1 << USB_DWC2_DOEPTSIZ0_SUPCNT_POS);
+		doeptsiz |= (3 << USB_DWC2_DOEPTSIZ0_SUPCNT_POS);
 	}
 
 	priv->rx_siz[ep_idx] = doeptsiz;
@@ -727,10 +726,17 @@ static void dwc2_handle_xfer_next(const struct device *dev,
 
 static int dwc2_ctrl_feed_dout(const struct device *dev, const size_t length)
 {
+	struct udc_dwc2_data *const priv = udc_get_private(dev);
 	struct udc_ep_config *ep_cfg = udc_get_ep_cfg(dev, USB_CONTROL_EP_OUT);
 	struct net_buf *buf;
+	size_t alloc_len = length;
+
+	if (dwc2_in_buffer_dma_mode(dev)) {
+		/* Control OUT buffers must be multiple of bMaxPacketSize0 */
+		alloc_len = ROUND_UP(length, 64);
+	}
 
-	buf = udc_ctrl_alloc(dev, USB_CONTROL_EP_OUT, length);
+	buf = udc_ctrl_alloc(dev, USB_CONTROL_EP_OUT, alloc_len);
 	if (buf == NULL) {
 		return -ENOMEM;
 	}