Commits
Pawel Laszczak committed 6bbf87a131e
usb:cdns3 Fix for stuck packets in on-chip OUT buffer. Controller for OUT endpoints has shared on-chip buffers for all incoming packets, including ep0out. It's FIFO buffer, so packets must be handled by DMA in correct order. If the first packet in the buffer will not be handled, then the following packets directed for other endpoints and functions will be blocked. Additionally the packets directed to one endpoint can block entire on-chip buffers. In this case transfer to other endpoints also will blocked. To resolve this issue after raising the descriptor missing interrupt driver prepares internal usb_request object and use it to arm DMA transfer. The problematic situation was observed in case when endpoint has been enabled but no usb_request were queued. Driver try detects such endpoints and will use this workaround only for these endpoint. Driver use limited number of buffer. This number can be set by macro CDNS_WA2_NUM_BUFFERS. Such blocking situation was observed on ACM gadget. For this function host send OUT data packet but ACM function is not prepared for this packet. It's cause that buffer placed in on chip memory block transfer to other endpoints. Issue has been fixed for DEV_VER_V2 version of controller. Signed-off-by: Pawel Laszczak <pawell@cadence.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>