On 2016/9/27 11:55, mgau...@codeaurora.org wrote:
On 2016-09-22 18:46, yfw wrote:
Hi list,
I tried to enable the high speed, high bandwidth transfer in device
mode for iso type on dwc3 based soc. The platform only supports usb
device 2.0.
I set the MaxPacketSize to 0x1400 so the host could allocate 3072
bytes for uframe. But when I chain three trbs together, the dwc3
behavior is quite weird:
Why are you using three TRBs for one service interval? Is the data
not contiguous?
Since, in your case all 3072 bytes belong to one service interval,
could just one TRB be used with PktCntM1 set to '2' ?
BTW, the configures:
1. 1 trb with one 3072 bytes buffer:
trb1: size set to DWC3_TRB_SIZE_PCM1(2) | 0xc00
DMA = Buffer DMA address
2. 3 trbs with one 3072 bytes buffer:
trb1: size DWC3_TRB_SIZE_PCM1(2) | 0x400, ctrl with CHN bit set
DMA = buffer DMA address
trb2: size: 0x400, ctrl with CHN bit set
DMA = buffer DMA address + 0x400
trb3: size: 0x400, ctrl with CHN bit NOT set
DMA = buffer DMA address + 0x800
should have same behavior. Right?
Regards
Yin, Fengwei
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