drivers: usb: device: usb_dc_stm32 issue USB drivers

Isochronous endpoint issue with USB drivers on STM32G491
we setup an isochronous endpoint and are having an issue
where every other frame sends the desired data sandwiched
between garbage data.

For isochronous the parameter ep_kind into the fonction :
HAL_PCDEx_PMAConfig(PCD_HandleTypeDef *hpcd, uint16_t ep_addr,
uint16_t ep_kind, uint32_t pmaadress) must be PCD_DBL_BUF.

The parameter pmaadress (EP address in The PMA) is like that:
EP address in The PMA: In case of single buffer endpoint
this parameter is 16-bit value providing the address
in PMA allocated to endpoint.
In case of double buffer endpoint this parameter
is a 32-bit value providing the endpoint buffer 0 address
in the LSB part of 32-bit value and endpoint buffer 1 address
in the MSB part of 32-bit value.


Signed-off-by: Marc Desvaux <[email protected]>

drivers/usb/device/usb_dc_stm32.c

@@ -639,20 +639,39 @@ int usb_dc_ep_configure(const struct usb_dc_ep_cfg_data * const ep_cfg)
 	LOG_DBG("ep 0x%02x, previous ep_mps %u, ep_mps %u, ep_type %u",
 		ep_cfg->ep_addr, ep_state->ep_mps, ep_cfg->ep_mps,
 		ep_cfg->ep_type);
-
 #if defined(USB) || defined(USB_DRD_FS)
 	if (ep_cfg->ep_mps > ep_state->ep_pma_buf_len) {
-		if (USB_RAM_SIZE <=
-		    (usb_dc_stm32_state.pma_offset + ep_cfg->ep_mps)) {
+		if (ep_cfg->ep_type == USB_DC_EP_ISOCHRONOUS) {
+			if (USB_RAM_SIZE <=
+			   (usb_dc_stm32_state.pma_offset + ep_cfg->ep_mps*2)) {
+				return -EINVAL;
+			}
+		} else if (USB_RAM_SIZE <=
+			  (usb_dc_stm32_state.pma_offset + ep_cfg->ep_mps)) {
 			return -EINVAL;
 		}
-		HAL_PCDEx_PMAConfig(&usb_dc_stm32_state.pcd, ep, PCD_SNG_BUF,
-				    usb_dc_stm32_state.pma_offset);
-		ep_state->ep_pma_buf_len = ep_cfg->ep_mps;
-		usb_dc_stm32_state.pma_offset += ep_cfg->ep_mps;
+
+		if (ep_cfg->ep_type == USB_DC_EP_ISOCHRONOUS) {
+			HAL_PCDEx_PMAConfig(&usb_dc_stm32_state.pcd, ep, PCD_DBL_BUF,
+				usb_dc_stm32_state.pma_offset +
+				((usb_dc_stm32_state.pma_offset + ep_cfg->ep_mps) << 16));
+			ep_state->ep_pma_buf_len = ep_cfg->ep_mps*2;
+			usb_dc_stm32_state.pma_offset += ep_cfg->ep_mps*2;
+		} else {
+			HAL_PCDEx_PMAConfig(&usb_dc_stm32_state.pcd, ep, PCD_SNG_BUF,
+				usb_dc_stm32_state.pma_offset);
+			ep_state->ep_pma_buf_len = ep_cfg->ep_mps;
+			usb_dc_stm32_state.pma_offset += ep_cfg->ep_mps;
+		}
 	}
-#endif
+	if (ep_cfg->ep_type == USB_DC_EP_ISOCHRONOUS) {
+		ep_state->ep_mps = ep_cfg->ep_mps*2;
+	} else {
+		ep_state->ep_mps = ep_cfg->ep_mps;
+	}
+#else
 	ep_state->ep_mps = ep_cfg->ep_mps;
+#endif
 
 	switch (ep_cfg->ep_type) {
 	case USB_DC_EP_CONTROL: