From: Matthias Goebl Date: Fri, 4 Jan 2008 11:45:28 +0000 (-0800) Subject: [ISDN]: i4l: Fix DLE handling for i4l-audio X-Git-Tag: v2.6.24-rc7~6^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7fde4d779b83898851959f837c9b26fe07ee91c9;p=linux-2.6 [ISDN]: i4l: Fix DLE handling for i4l-audio The DLE handling in i4l-audio seems to be broken. It produces spurious DLEs so asterisk 1.2.24 with chan_modem_i4l gets irritated, the error message is: "chan_modem_i4l.c:450 i4l_read: Value of escape is ^ (17)". -> There shouldn't be a DLE-^. If a spurious DLE-ETX occurs, the audio connection even dies. I use a "AVM Fritz!PCI" isdn card. I found two issues that only appear if ISDN_AUDIO_SKB_DLECOUNT(skb) > 0: - The loop in isdn_tty.c:isdn_tty_try_read() doesn't escape a DLE if it's the last character. - The loop in isdn_common.c:isdn_readbchan_tty() doesn't copy its characters, it only remembers the last one ("last = *p;"). Compare it with the loop in isdn_common.c:isdn_readbchan(), that *does* copy them ("*cp++ = *p;") correctly. The special handling of the "last" character made it more difficult. I compared it to linux-2.4.19: There was no "last"-handling and both loops did escape and copy all characters correctly. Signed-off-by: Matthias Goebl Signed-off-by: David S. Miller --- diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c index d6952959d7..9cef6fcf58 100644 --- a/drivers/isdn/i4l/isdn_common.c +++ b/drivers/isdn/i4l/isdn_common.c @@ -914,6 +914,9 @@ isdn_readbchan_tty(int di, int channel, struct tty_struct *tty, int cisco_hack) dflag = 0; count_pull = count_put = 0; while ((count_pull < skb->len) && (len > 0)) { + /* push every character but the last to the tty buffer directly */ + if ( count_put ) + tty_insert_flip_char(tty, last, TTY_NORMAL); len--; if (dev->drv[di]->DLEflag & DLEmask) { last = DLE; diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c index 24679a3f55..9cb6e5021a 100644 --- a/drivers/isdn/i4l/isdn_tty.c +++ b/drivers/isdn/i4l/isdn_tty.c @@ -85,6 +85,8 @@ isdn_tty_try_read(modem_info * info, struct sk_buff *skb) tty_insert_flip_char(tty, DLE, 0); tty_insert_flip_char(tty, *dp++, 0); } + if (*dp == DLE) + tty_insert_flip_char(tty, DLE, 0); last = *dp; } else { #endif