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devusb: keep isochronous ep->hz consistent with maxpkt, ntds and pollival

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The sample frequency is an artificial parameter used for
isochronous out transfers to better match the target
frequency (usually, a sound card).

when hz is set, devusb adjusts the endpoint's maxpkt to get
the requested frequency and a multiple of the samplesize per
packet.

however, when hz is not set, then we should calculate the
frequency from maxpkt, ntds and pollival, so all parameters
will be consistent with each other.
This commit is contained in:
cinap_lenrek 2020-06-21 21:36:50 +02:00
parent 78a6eb52c8
commit 4fb65ae3e8
1 changed files with 62 additions and 42 deletions
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104
sys/src/9/port/devusb.c
View file

@ -525,8 +525,8 @@ newdevep(Ep *ep, int i, int tt, int mode)
case Tiso:
nep->tmout = Xfertmout;
nep->pollival = 10;
nep->samplesz = 4;
nep->hz = 44100;
nep->samplesz = 1;
nep->hz = 0;
nep->uframes = 0;
break;
}
@ -859,6 +859,58 @@ usbload(int speed, int maxpkt)
return l / 1000UL; /* in µs */
}
static void
isotiming(Ep *ep)
{
long spp, max;
switch(ep->dev->speed){
case Fullspeed:
max = 1024;
break;
case Highspeed:
max = 3*1024;
break;
case Superspeed:
max = 48*1024;
break;
default:
error(Egreg);
return;
}
if(ep->ntds <= 0)
error(Egreg);
max /= ep->ntds;
if(max < ep->samplesz)
error(Egreg);
if(ep->pollival <= 0)
error(Egreg);
if(ep->hz <= 0){
spp = ep->maxpkt / ep->samplesz;
spp *= ep->ntds;
if(ep->dev->speed == Fullspeed || ep->dev->speed == Lowspeed)
ep->hz = (1000 * spp) / ep->pollival;
else
ep->hz = (8000 * spp) / ep->pollival;
if(ep->hz <= 0)
error(Egreg);
}
if(ep->dev->speed == Fullspeed || ep->dev->speed == Lowspeed)
spp = (ep->hz * ep->pollival + 999) / 1000;
else
spp = (ep->hz * ep->pollival + 7999) / 8000;
spp /= ep->ntds;
ep->maxpkt = spp * ep->samplesz;
if(ep->maxpkt > max){
print("ep%d.%d: maxpkt %ld > %ld for %s, truncating\n",
ep->dev->nb, ep->nb,
ep->maxpkt, max, spname[ep->dev->speed]);
ep->maxpkt = max;
}
}
static Chan*
usbopen(Chan *c, int omode)
{
@ -901,6 +953,9 @@ usbopen(Chan *c, int omode)
error(Enotconf);
ep->clrhalt = 0;
ep->rhrepl = -1;
if(ep->ttype == Tiso)
isotiming(ep);
if(ep->load == 0 && ep->dev->speed != Superspeed)
ep->load = usbload(ep->dev->speed, ep->maxpkt);
ep->hp->epopen(ep);
@ -1159,40 +1214,6 @@ usbread(Chan *c, void *a, long n, vlong offset)
return n;
}
static void
setmaxpkt(Ep *ep, char* s)
{
long spp, max; /* samples per packet */
if(ep->dev->speed == Fullspeed)
spp = (ep->hz * ep->pollival + 999) / 1000;
else
spp = (ep->hz * ep->pollival * ep->ntds + 7999) / 8000;
ep->maxpkt = spp * ep->samplesz;
deprint("usb: %s: setmaxpkt: hz %ld poll %ld"
" ntds %d %s speed -> spp %ld maxpkt %ld\n", s,
ep->hz, ep->pollival, ep->ntds, spname[ep->dev->speed],
spp, ep->maxpkt);
switch(ep->dev->speed){
case Fullspeed:
max = 1024;
break;
case Highspeed:
max = 3*1024;
break;
case Superspeed:
max = 48*1024;
break;
default:
return;
}
if(ep->maxpkt*ep->ntds > max){
print("usb: %s: maxpkt %ld > %ld for %s, truncating\n",
s, ep->maxpkt*ep->ntds, max, spname[ep->dev->speed]);
ep->maxpkt = max/ep->ntds;
}
}
/*
* Many endpoint ctls. simply update the portable representation
* of the endpoint. The actual controller driver will look
@ -1287,6 +1308,7 @@ epctl(Ep *ep, Chan *c, void *a, long n)
error("maxpkt not in [1:1024]");
qlock(ep);
ep->maxpkt = l;
ep->hz = 0; /* recalculate */
qunlock(ep);
break;
case CMntds:
@ -1296,6 +1318,7 @@ epctl(Ep *ep, Chan *c, void *a, long n)
error("ntds not in [1:3]");
qlock(ep);
ep->ntds = l;
ep->hz = 0; /* recalculate */
qunlock(ep);
break;
case CMpollival:
@ -1313,8 +1336,7 @@ epctl(Ep *ep, Chan *c, void *a, long n)
}
qlock(ep);
ep->pollival = l;
if(ep->ttype == Tiso)
setmaxpkt(ep, "pollival");
ep->hz = 0; /* recalculate */
qunlock(ep);
break;
case CMsamplesz:
@ -1326,7 +1348,6 @@ epctl(Ep *ep, Chan *c, void *a, long n)
error("samplesz not in [1:8]");
qlock(ep);
ep->samplesz = l;
setmaxpkt(ep, "samplesz");
qunlock(ep);
break;
case CMhz:
@ -1334,11 +1355,10 @@ epctl(Ep *ep, Chan *c, void *a, long n)
error("not an iso endpoint");
l = strtoul(cb->f[1], nil, 0);
deprint("usb epctl %s %d\n", cb->f[0], l);
if(l <= 0 || l > 100000)
error("hz not in [1:100000]");
if(l <= 0 || l > 1000000000)
error("hz not in [1:1000000000]");
qlock(ep);
ep->hz = l;
setmaxpkt(ep, "hz");
qunlock(ep);
break;
case CMuframes: