| Message ID | 1466432945-28682-4-git-send-email-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
* Paolo Bonzini (pbonzini@redhat.com) wrote: > serial_xmit starts transmission of whatever is in the FIFO or THR; > serial_watch_cb is a wrapper around it. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > hw/char/serial.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/hw/char/serial.c b/hw/char/serial.c > index 6f0a49e..4196a2e 100644 > --- a/hw/char/serial.c > +++ b/hw/char/serial.c > @@ -106,6 +106,7 @@ do {} while (0) > #endif > > static void serial_receive1(void *opaque, const uint8_t *buf, int size); > +static void serial_xmit(SerialState *s); > > static inline void recv_fifo_put(SerialState *s, uint8_t chr) > { > @@ -223,10 +224,16 @@ static void serial_update_msl(SerialState *s) > } > } > > -static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) > +static gboolean serial_watch_cb(GIOChannel *chan, GIOCondition cond, > + void *opaque) > { > SerialState *s = opaque; > + serial_xmit(s); > + return FALSE; > +} Yes, with a side question. We register this with G_IO_OUT|G_IO_HUP but don't check the cond, what's this code supposed to do if it gets a HUP? Since we didn't do anything with cond before either: Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > +static void serial_xmit(SerialState *s) > +{ > do { > assert(!(s->lsr & UART_LSR_TEMT)); > if (s->tsr_retry == 0) { > @@ -254,9 +261,9 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) > } else if (qemu_chr_fe_write(s->chr, &s->tsr, 1) != 1) { > if (s->tsr_retry < MAX_XMIT_RETRY && > qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, > - serial_xmit, s) > 0) { > + serial_watch_cb, s) > 0) { > s->tsr_retry++; > - return FALSE; > + return; > } > s->tsr_retry = 0; > } else { > @@ -269,11 +276,8 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) > > s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > s->lsr |= UART_LSR_TEMT; > - > - return FALSE; > } > > - > /* Setter for FCR. > is_load flag means, that value is set while loading VM state > and interrupt should not be invoked */ > @@ -331,7 +335,7 @@ static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val, > s->lsr &= ~UART_LSR_TEMT; > serial_update_irq(s); > if (s->tsr_retry == 0) { > - serial_xmit(NULL, G_IO_OUT, s); > + serial_xmit(s); > } > } > break; > @@ -647,7 +651,8 @@ static int serial_post_load(void *opaque, int version_id) > } > > assert(s->watch_tag == 0); > - s->watch_tag = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, serial_xmit, s); > + s->watch_tag = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, > + serial_watch_cb, s); > } else { > /* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */ > if (!(s->lsr & UART_LSR_TEMT)) { > -- > 2.5.5 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 22/06/2016 17:09, Dr. David Alan Gilbert wrote: > > -static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) > > +static gboolean serial_watch_cb(GIOChannel *chan, GIOCondition cond, > > + void *opaque) > > { > > SerialState *s = opaque; > > + serial_xmit(s); > > + return FALSE; > > +} > > Yes, with a side question. > We register this with G_IO_OUT|G_IO_HUP but don't check the cond, what's this > code supposed to do if it gets a HUP? It will attempt again to write, which will fail (see pty_chr_write); then attempt to add a watch again, which this time should return 0 (see pty_chr_add_watch). The outcome is that tsr_retry is reset to 0. Thanks, Paolo > Since we didn't do anything with cond before either: > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > >
diff --git a/hw/char/serial.c b/hw/char/serial.c index 6f0a49e..4196a2e 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -106,6 +106,7 @@ do {} while (0) #endif static void serial_receive1(void *opaque, const uint8_t *buf, int size); +static void serial_xmit(SerialState *s); static inline void recv_fifo_put(SerialState *s, uint8_t chr) { @@ -223,10 +224,16 @@ static void serial_update_msl(SerialState *s) } } -static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) +static gboolean serial_watch_cb(GIOChannel *chan, GIOCondition cond, + void *opaque) { SerialState *s = opaque; + serial_xmit(s); + return FALSE; +} +static void serial_xmit(SerialState *s) +{ do { assert(!(s->lsr & UART_LSR_TEMT)); if (s->tsr_retry == 0) { @@ -254,9 +261,9 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) } else if (qemu_chr_fe_write(s->chr, &s->tsr, 1) != 1) { if (s->tsr_retry < MAX_XMIT_RETRY && qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, - serial_xmit, s) > 0) { + serial_watch_cb, s) > 0) { s->tsr_retry++; - return FALSE; + return; } s->tsr_retry = 0; } else { @@ -269,11 +276,8 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); s->lsr |= UART_LSR_TEMT; - - return FALSE; } - /* Setter for FCR. is_load flag means, that value is set while loading VM state and interrupt should not be invoked */ @@ -331,7 +335,7 @@ static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val, s->lsr &= ~UART_LSR_TEMT; serial_update_irq(s); if (s->tsr_retry == 0) { - serial_xmit(NULL, G_IO_OUT, s); + serial_xmit(s); } } break; @@ -647,7 +651,8 @@ static int serial_post_load(void *opaque, int version_id) } assert(s->watch_tag == 0); - s->watch_tag = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, serial_xmit, s); + s->watch_tag = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, + serial_watch_cb, s); } else { /* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */ if (!(s->lsr & UART_LSR_TEMT)) {
serial_xmit starts transmission of whatever is in the FIFO or THR; serial_watch_cb is a wrapper around it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- hw/char/serial.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)