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Add a jitter buffer in the common USB serial driver code which

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temporarily stores characters if the TTY buffer is full when
used a as a console. This can happen when a console is suspended.
Also properly do the flow stop signalling when this happens and
flow start when the condition changes back to normal again.

Bump __FreeBSD_version to force external kernel modules
to be recompiled. No kernel API changes.

MFC after:	1 week
Suggested by:	ed @
This commit is contained in:
Hans Petter Selasky 2012-11-05 17:50:40 +00:00
parent 417a0a79d7
commit d30d96ea57
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=242619
3 changed files with 82 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

79
sys/dev/usb/serial/usb_serial.c
View File

@ -162,6 +162,7 @@ static tsw_ioctl_t ucom_ioctl;
static tsw_modem_t ucom_modem;
static tsw_param_t ucom_param;
static tsw_outwakeup_t ucom_outwakeup;
static tsw_inwakeup_t ucom_inwakeup;
static tsw_free_t ucom_free;
static struct ttydevsw ucom_class = {
@ -169,6 +170,7 @@ static struct ttydevsw ucom_class = {
.tsw_open = ucom_open,
.tsw_close = ucom_close,
.tsw_outwakeup = ucom_outwakeup,
.tsw_inwakeup = ucom_inwakeup,
.tsw_ioctl = ucom_ioctl,
.tsw_param = ucom_param,
.tsw_modem = ucom_modem,
@ -716,6 +718,10 @@ ucom_open(struct tty *tp)
sc->sc_pls_set = 0;
sc->sc_pls_clr = 0;
/* reset jitter buffer */
sc->sc_jitterbuf_in = 0;
sc->sc_jitterbuf_out = 0;
ucom_queue_command(sc, ucom_cfg_open, NULL,
&sc->sc_open_task[0].hdr,
&sc->sc_open_task[1].hdr);
@ -780,6 +786,47 @@ ucom_close(struct tty *tp)
}
}
static void
ucom_inwakeup(struct tty *tp)
{
struct ucom_softc *sc = tty_softc(tp);
uint16_t pos;
if (sc == NULL)
return;
tty_lock(tp);
if (ttydisc_can_bypass(tp) != 0 ||
(sc->sc_flag & UCOM_FLAG_HL_READY) == 0) {
tty_unlock(tp);
return;
}
pos = sc->sc_jitterbuf_out;
while (sc->sc_jitterbuf_in != pos) {
int c;
c = (char)sc->sc_jitterbuf[pos];
if (ttydisc_rint(tp, c, 0) == -1)
break;
pos++;
if (pos >= UCOM_JITTERBUF_SIZE)
pos -= UCOM_JITTERBUF_SIZE;
}
sc->sc_jitterbuf_out = pos;
/* clear RTS in async fashion */
if ((sc->sc_jitterbuf_in == pos) &&
(sc->sc_flag & UCOM_FLAG_RTS_IFLOW))
ucom_rts(sc, 0);
tty_unlock(tp);
}
static int
ucom_ioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
{
@ -1360,6 +1407,11 @@ ucom_put_data(struct ucom_softc *sc, struct usb_page_cache *pc,
/* first check if we can pass the buffer directly */
if (ttydisc_can_bypass(tp)) {
/* clear any jitter buffer */
sc->sc_jitterbuf_in = 0;
sc->sc_jitterbuf_out = 0;
if (ttydisc_rint_bypass(tp, buf, cnt) != cnt) {
DPRINTF("tp=%p, data lost\n", tp);
}
@ -1368,8 +1420,31 @@ ucom_put_data(struct ucom_softc *sc, struct usb_page_cache *pc,
/* need to loop */
for (cnt = 0; cnt != res.length; cnt++) {
if (ttydisc_rint(tp, buf[cnt], 0) == -1) {
/* XXX what should we do? */
if (sc->sc_jitterbuf_in != sc->sc_jitterbuf_out ||
ttydisc_rint(tp, buf[cnt], 0) == -1) {
uint16_t end;
uint16_t pos;
pos = sc->sc_jitterbuf_in;
end = sc->sc_jitterbuf_out +
UCOM_JITTERBUF_SIZE - 1;
if (end >= UCOM_JITTERBUF_SIZE)
end -= UCOM_JITTERBUF_SIZE;
for (; cnt != res.length; cnt++) {
if (pos == end)
break;
sc->sc_jitterbuf[pos] = buf[cnt];
pos++;
if (pos >= UCOM_JITTERBUF_SIZE)
pos -= UCOM_JITTERBUF_SIZE;
}
sc->sc_jitterbuf_in = pos;
/* set RTS in async fashion */
if (sc->sc_flag & UCOM_FLAG_RTS_IFLOW)
ucom_rts(sc, 1);
DPRINTF("tp=%p, lost %d "
"chars\n", tp, res.length - cnt);

4
sys/dev/usb/serial/usb_serial.h
View File

@ -78,6 +78,7 @@
#define UCOM_MINVER 1
#define UCOM_PREFVER UCOM_MODVER
#define UCOM_MAXVER 1
#define UCOM_JITTERBUF_SIZE 128 /* bytes */
struct usb_device;
struct ucom_softc;
@ -169,6 +170,8 @@ struct ucom_softc {
struct mtx *sc_mtx;
void *sc_parent;
int sc_subunit;
uint16_t sc_jitterbuf_in;
uint16_t sc_jitterbuf_out;
uint16_t sc_portno;
uint16_t sc_flag;
#define UCOM_FLAG_RTS_IFLOW 0x01 /* use RTS input flow control */
@ -191,6 +194,7 @@ struct ucom_softc {
#define UCOM_LS_RTS 0x02
#define UCOM_LS_BREAK 0x04
#define UCOM_LS_RING 0x08
uint8_t sc_jitterbuf[UCOM_JITTERBUF_SIZE];
};
#define UCOM_MTX_ASSERT(sc, what) mtx_assert((sc)->sc_mtx, what)

2
sys/sys/param.h
View File

@ -58,7 +58,7 @@
* in the range 5 to 9.
*/
#undef __FreeBSD_version
#define __FreeBSD_version 1000022 /* Master, propagated to newvers */
#define __FreeBSD_version 1000023 /* Master, propagated to newvers */
/*
* __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,