Author: hselasky Date: Thu Dec 12 08:34:51 2013 New Revision: 259248 URL: http://svnweb.freebsd.org/changeset/base/259248
Log: Set chain bit correctly. This will fix some problems sending and receiving Zero Length Packets, ZLPs. See comment in code for more information. MFC after: 1 week Reported by: Kohji Okuno <[email protected]> Modified: head/sys/dev/usb/controller/xhci.c Modified: head/sys/dev/usb/controller/xhci.c ============================================================================== --- head/sys/dev/usb/controller/xhci.c Thu Dec 12 08:23:28 2013 (r259247) +++ head/sys/dev/usb/controller/xhci.c Thu Dec 12 08:34:51 2013 (r259248) @@ -1892,7 +1892,16 @@ restart: td->td_trb[x].dwTrb2 = htole32(dword); dword = XHCI_TRB_3_TYPE_SET(XHCI_TRB_TYPE_LINK) | - XHCI_TRB_3_CYCLE_BIT | XHCI_TRB_3_IOC_BIT; + XHCI_TRB_3_CYCLE_BIT | XHCI_TRB_3_IOC_BIT | + /* + * CHAIN-BIT: Ensure that a multi-TRB IN-endpoint + * frame only receives a single short packet event + * by setting the CHAIN bit in the LINK field. In + * addition some XHCI controllers have problems + * sending a ZLP unless the CHAIN-BIT is set in + * the LINK TRB. + */ + XHCI_TRB_3_CHAIN_BIT; td->td_trb[x].dwTrb3 = htole32(dword); @@ -1930,7 +1939,7 @@ restart: } /* clear TD SIZE to zero, hence this is the last TRB */ - /* remove chain bit because this is the last TRB in the chain */ + /* remove chain bit because this is the last data TRB in the chain */ td->td_trb[td->ntrb - 1].dwTrb2 &= ~htole32(XHCI_TRB_2_TDSZ_SET(15)); td->td_trb[td->ntrb - 1].dwTrb3 &= ~htole32(XHCI_TRB_3_CHAIN_BIT); _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
