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| author | Keir Fraser <keir.fraser@citrix.com> | 2007-12-06 10:41:10 +0000 |
|---|---|---|
| committer | Keir Fraser <keir.fraser@citrix.com> | 2007-12-06 10:41:10 +0000 |
| commit | 5048bfb26073bffccc96a0cd2eee8306caa8e82e (patch) | |
| tree | 2ab5d6f842cc09f76fbff98ce7d33ca0cbc13078 | |
| parent | 3d87f3ac6c4aeffd0e93cacd8956474c194b6989 (diff) | |
| download | xen-5048bfb26073bffccc96a0cd2eee8306caa8e82e.tar.gz xen-5048bfb26073bffccc96a0cd2eee8306caa8e82e.tar.bz2 xen-5048bfb26073bffccc96a0cd2eee8306caa8e82e.zip | |
qemu-dm: Limit transmit retries from virtual UART FIFO.
Signed-off-by: Trolle Selander <trolle.selander@gmail.com>
| -rw-r--r-- | tools/ioemu/hw/serial.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/tools/ioemu/hw/serial.c b/tools/ioemu/hw/serial.c index 9523a66623..eefb9651b1 100644 --- a/tools/ioemu/hw/serial.c +++ b/tools/ioemu/hw/serial.c @@ -96,6 +96,7 @@ #define XMIT_FIFO 0 #define RECV_FIFO 1 +#define MAX_XMIT_RETRY 4 struct SerialFIFO { uint8_t data[UART_FIFO_LENGTH]; @@ -136,7 +137,7 @@ struct SerialState { struct QEMUTimer *fifo_timeout_timer; int timeout_ipending; /* timeout interrupt pending state */ - struct QEMUTimer *fifo_transmit_timer; + struct QEMUTimer *transmit_timer; uint64_t char_transmit_time; /* time to transmit a char in ticks*/ @@ -370,15 +371,17 @@ static void serial_xmit(void *opaque) { if ( qemu_chr_write(s->chr, &s->tsr, 1) != 1 ) { s->tsr_retry++; - qemu_mod_timer(s->fifo_transmit_timer, new_xmit_ts + s->char_transmit_time ); - return; + if ( s->tsr_retry <= MAX_XMIT_RETRY ) { + qemu_mod_timer(s->transmit_timer, new_xmit_ts + s->char_transmit_time ); + return; + } } s->tsr_retry = 0; s->last_xmit_ts = qemu_get_clock(vm_clock); - if ( s->xmit_fifo.count > 0 ) - qemu_mod_timer(s->fifo_transmit_timer, s->last_xmit_ts + s->char_transmit_time ); + if ( !(s->lsr & UART_LSR_THRE) ) + qemu_mod_timer(s->transmit_timer, s->last_xmit_ts + s->char_transmit_time ); if ( s->lsr & UART_LSR_THRE ) { s->lsr |= UART_LSR_TEMT; @@ -752,7 +755,7 @@ SerialState *serial_init(SetIRQFunc *set_irq, void *opaque, fifo_clear(s,XMIT_FIFO); s->last_xmit_ts = qemu_get_clock(vm_clock); s->fifo_timeout_timer = qemu_new_timer(vm_clock, ( QEMUTimerCB *) fifo_timeout_int, s); - s->fifo_transmit_timer = qemu_new_timer(vm_clock, ( QEMUTimerCB *) serial_xmit, s); + s->transmit_timer = qemu_new_timer(vm_clock, ( QEMUTimerCB *) serial_xmit, s); register_savevm("serial", base, 2, serial_save, serial_load, s); |