[9fans] Tdmaxpkt in usbehci
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? -- cinap
[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? -- cinap PS: sorry for the previous mail. i was sending it with web mail which i use very rarely and the default setting for email was to send them as HTML :(
[9fans] International Ispell in Plan9
> And you can have '>> /personal/dictionary/path' [...] Sorry, this must be 'echo >> /personal/dictionary/path' and make a 2-1 mouse chord. Regards, trebol.
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
Re: [9fans] Tdmaxpkt in usbehci (no html)
yes, that would work too. -- cinap > Gesendet: Donnerstag, 11. April 2013 um 15:05 Uhr > Von: "erik quanstrom" > 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 > >
[9fans] wired loop in usbehci / isohsinit()
this td->buffer[i] access makes no sense.
static void
isohsinit(Ep *ep, Isoio *iso)
{
int ival, p;
long left;
ulong frno, i, pa;
Itd *ltd, *td;
iso->hs = 1;
ival = 1;
if(ep->pollival > 8)
ival = ep->pollival/8;
left = 0;
ltd = nil;
frno = iso->td0frno;
for(i = 0; i < iso->nframes; i++){
td = itdalloc();
td->data = iso->data + i * 8 * iso->maxsize;
pa = PADDR(td->data) & ~0xFFF;
for(p = 0; p < 8; p++)
td->buffer[i] = pa + p * 0x1000; // <- HERE
td->buffer[0] = PADDR(iso->data) & ~0xFFF |
ep->nb << Itdepshift | ep->dev->nb << Itddevshift;
if(ep->mode == OREAD)
td->buffer[1] |= Itdin;
else
td->buffer[1] |= Itdout;
td->buffer[1] |= ep->maxpkt << Itdmaxpktshift;
td->buffer[2] |= ep->ntds << Itdntdsshift;
if(ep->mode == OREAD)
td->mdata = 8 * iso->maxsize;
else{
td->mdata = (ep->hz + left) * ep->pollival / 1000;
td->mdata *= ep->samplesz;
left = (ep->hz + left) * ep->pollival % 1000;
}
coherence();
iso->itdps[frno] = td;
coherence();
itdinit(iso, td);
if(ltd != nil)
ltd->next = td;
ltd = td;
frno = TRUNC(frno + ival, Nisoframes);
}
}
--
cinap
Re: [9fans] International Ispell in Plan9
you could put it in sources, if not yet there.
