usb: dwc3: gadget: Handle DEV_TXF_FLUSH_BYPASS capability
DWC_usb32 IP introduces a new behavior when handling NoStream event for
IN endpoints. If the controller is capable of DEV_TXF_FLUSH_BYPASS, then
the driver does not need to force to restart stream for IN endpoints.
The controller will generate ERDY and restart the stream periodically.
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/65c3070c666cd6b8beeee62d7f8e3e704ebf2d32.1619134559.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 90f4f9e..dd80e5c 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -730,8 +730,16 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep, unsigned int action)
* All stream eps will reinitiate stream on NoStream
* rejection until we can determine that the host can
* prime after the first transfer.
+ *
+ * However, if the controller is capable of
+ * TXF_FLUSH_BYPASS, then IN direction endpoints will
+ * automatically restart the stream without the driver
+ * initiation.
*/
- dep->flags |= DWC3_EP_FORCE_RESTART_STREAM;
+ if (!dep->direction ||
+ !(dwc->hwparams.hwparams9 &
+ DWC3_GHWPARAMS9_DEV_TXF_FLUSH_BYPASS))
+ dep->flags |= DWC3_EP_FORCE_RESTART_STREAM;
}
}