Dear Sergei, ? 2018?04?24? 16:27, Sergei Shtylyov ??: > Hello! > > On 4/24/2018 5:43 AM, William Wu wrote: > >> If isoc split in transfer with no data (the length of DATA0 >> packet is 0), we can't simply return immediately. Because the >> DATA0 can be the first transaction or the second transaction for >> the isoc split in transaction. If the DATA0 packet with on data > ????????????????????????????????????????????????????????? ^^ no? Thank you for correcting me. I will fix it in next patch version. > >> is in the first transaction, we can return immediately. But if >> the the DATA0 packet with on data is in the second transaction > > ? One "the" too many. And that "on data" again... :-) Ah, sorry to make such a simple mistake. I will fix these in next patch version. > >> of isoc split in transaction sequence, we need to increase the >> qtd->isoc_frame_index and giveback urb to device driver if needed, >> otherwise, the MDATA packet will be lost. >> >> A typical test case is that connect the dwc2 controller with an >> usb hs Hub (GL852G-12), and plug an usb fs audio device (Plantronics >> headset) into the downstream port of Hub. Then use the usb mic >> to record, we can find noise when playback. >> >> In the case, the isoc split in transaction sequence like this: >> >> - SSPLIT IN transaction >> - CSPLIT IN transaction >> ?? - MDATA packet (176 bytes) >> - CSPLIT IN transaction >> ?? - DATA0 packet (0 byte) >> >> This patch use both the length of DATA0 and qtd->isoc_split_offset >> to check if the DATA0 is in the second transaction. >> >> Signed-off-by: William Wu <william.wu at rock-chips.com> > [...] > > MBR, Sergei Best regards, ??? wulf > > >
