svn commit: r331306 - head/sys/dev/usb/controller

Hans Petter Selasky hps at selasky.org
Wed Mar 21 21:54:15 UTC 2018


On 03/21/18 17:45, Andrew Turner wrote:
> 
> 
>> On 21 Mar 2018, at 15:37, Hans Petter Selasky <hps at selasky.org> wrote:
>>
>> On 03/21/18 16:24, Kyle Evans wrote:
>>>> +       {
>>>> +               .ep_end = 7,
>>>> +               .ep_fifosz_shift = 9,
>>>> +               .ep_fifosz_reg = MUSB2_VAL_FIFOSZ_512 | MUSB2_MASK_FIFODB,
>>>> +       },
>>> I'm afraid I'm not familiar with this- why did .ep_fifosz_shift for
>>> this case drop to 9? frx = 10 in the temp < 8 case in the removals of
>>> the following hunks. Mostly curious because the others seemed to stay
>>> the same.
>>
>> Hi Andrew,
>>
>> It might be an idea to keep the fifosz_shift at 10, else high-speed BULK traffic won't be double buffered, and this might affect performance.
> 
> Should the endpoint 1 size also be fixed? The register has it at 4k, but it wasn’t an 8k buffer.
> 

No, because High-Speed BULK will only use 512 byte packets, and 4k is 
reserved for isochronous, which doesn't need double buffering at the moment.

--HPS



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