Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> 於 2020年6月16日 週二 下午10:05寫道： > > On Tue, Jun 16, 2020 at 08:34:43PM +0800, Macpaul Lin wrote: > > Some USB hardware like DMA engine can help to process (split) the data > > of each URB request into small packets. For example, the max packet size > > of high speed is 512 bytes. These kinds of hardware can help to split > > the continue Tx/Rx data requests into packets just at the max packet > > size during transmission. Hence upper layer software can reduce some > > effort for queueing many requests back and forth for larger data. > > > > Here we introduce "can_exceed_maxp" flag in gadget when these kinds of > > hardware is ready to support these operations. > > This isn't needed. All UDC drivers must be able to support requests that > are larger than the maxpacket size. > > Alan Stern Thanks for your reply, could we just modify the patch 2 (u_serial.c) for improving better performance? I'm not sure why there was a restriction about max packet. Isn't there any historical reason? -- Best regards, Macpaul Lin
