yes, that would work too. -- cinap
> Gesendet: Donnerstag, 11. April 2013 um 15:05 Uhr > Von: "erik quanstrom" <quans...@quanstro.net> > An: 9fans@9fans.net > Betreff: Re: [9fans] Tdmaxpkt in usbehci (no html) > > > in the ehci driver, it uses: > > > > Tdmaxpkt = 0x5000, /* max buffer for a Td */ > > > > a td has 5*4K pages giving the 20K above, but i think this only applies if > > the > > first pointer is page aligned (page offset = 0) so all the pages can be > > filled > > completely. > > > > The EHCI spec says this: > > "The buffer pointer list in the qTD is long enough to support a maximum > > transfer size of 20K bytes. This case > > occurs when all five buffer pointers are used and the first offset is zero. > > A qTD handles a 16Kbyte buffer > > with any starting buffer alignment." > > > > The buffer pointer isnt page aligned as far as i can see, so make Tdmaxpkt > > = 0x4000 instead? > > i wonder if it would make more sense to align the buffer. > > (the unaligned case for iso->data looks wierd, too.) > > - erik > >
