diff options
| author | cinap_lenrek <cinap_lenrek@gmx.de> | 2012-09-03 01:54:34 +0200 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@gmx.de> | 2012-09-03 01:54:34 +0200 |
| commit | cfd25faa2857ee9de75910d81530be62d7ba4704 (patch) | |
| tree | 1bebf05a269d6923290e5e362a5bdf46fda6e8f4 /sys/src/9/port/usbehci.c | |
| parent | 1be10947ba37964feb10e0cf45576b029043866b (diff) | |
usb: fix isowrite putsamples race
Diffstat (limited to 'sys/src/9/port/usbehci.c')
| -rw-r--r-- | sys/src/9/port/usbehci.c | 47 |
1 files changed, 28 insertions, 19 deletions
diff --git a/sys/src/9/port/usbehci.c b/sys/src/9/port/usbehci.c index ef1c1ca71..22af2e798 100644 --- a/sys/src/9/port/usbehci.c +++ b/sys/src/9/port/usbehci.c @@ -1996,33 +1996,44 @@ episoread(Ep *ep, Isoio *iso, void *a, long count) * it is activated and tdu advanced. */ static long -putsamples(Isoio *iso, uchar *b, long count) +putsamples(Ctlr *ctlr, Isoio *iso, uchar *b, long count) { - long tot, n; + long left, tot, n; + Sitd *stdu; + Itd *tdu; for(tot = 0; isocanwrite(iso) && tot < count; tot += n){ n = count-tot; + left = iso->nleft; if(iso->hs != 0){ - if(n > iso->tdu->mdata - iso->nleft) - n = iso->tdu->mdata - iso->nleft; - memmove(iso->tdu->data + iso->nleft, b + tot, n); - coherence(); + tdu = iso->tdu; + if(n > tdu->mdata - left) + n = tdu->mdata - left; + iunlock(ctlr); /* We could page fault here */ + memmove(tdu->data + left, b + tot, n); + ilock(ctlr); + if(iso->tdu != tdu) + continue; iso->nleft += n; - if(iso->nleft == iso->tdu->mdata){ - itdinit(iso, iso->tdu); + if(iso->nleft == tdu->mdata){ + itdinit(iso, tdu); + iso->tdu = tdu->next; iso->nleft = 0; - iso->tdu = iso->tdu->next; } }else{ - if(n > iso->stdu->mdata - iso->nleft) - n = iso->stdu->mdata - iso->nleft; - memmove(iso->stdu->data + iso->nleft, b + tot, n); - coherence(); + stdu = iso->stdu; + if(n > stdu->mdata - left) + n = stdu->mdata - left; + iunlock(ctlr); /* We could page fault here */ + memmove(stdu->data + left, b + tot, n); + ilock(ctlr); + if(iso->stdu != stdu) + continue; iso->nleft += n; - if(iso->nleft == iso->stdu->mdata){ - sitdinit(iso, iso->stdu); + if(iso->nleft == stdu->mdata){ + sitdinit(iso, stdu); + iso->stdu = stdu->next; iso->nleft = 0; - iso->stdu = iso->stdu->next; } } } @@ -2081,9 +2092,7 @@ episowrite(Ep *ep, Isoio *iso, void *a, long count) } if(iso->state != Qrun) panic("episowrite: iso not running"); - iunlock(ctlr); /* We could page fault here */ - nw = putsamples(iso, b+tot, count-tot); - ilock(ctlr); + nw = putsamples(ctlr, iso, b+tot, count-tot); } while(isodelay(iso) == 0){ iunlock(ctlr); |