Re: [PATCH 1/2] usb: gadget: introduce flag for large request
From: Alan Stern <stern@rowland.harvard.edu>
Date: 2020-06-16 14:02:50
Also in:
linux-mediatek, linux-usb, lkml
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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel