On 22/06/2016 17:05, Dr. David Alan Gilbert wrote:
> * Paolo Bonzini (pbonz...@redhat.com) wrote:
>> Otherwise, a serial port can get stuck if it is migrated while flow control
>> is in effect.
>>
>> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
>> ---
>> hw/char/serial.c | 16 ++++++++++++++--
>> include/hw/char/serial.h | 1 +
>> 2 files changed, 15 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/char/serial.c b/hw/char/serial.c
>> index e65e9e0..6f0a49e 100644
>> --- a/hw/char/serial.c
>> +++ b/hw/char/serial.c
>> @@ -639,8 +639,20 @@ static int serial_post_load(void *opaque, int
>> version_id)
>> if (s->thr_ipending == -1) {
>> s->thr_ipending = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
>> }
>> - if (s->tsr_retry > MAX_XMIT_RETRY) {
>> - s->tsr_retry = MAX_XMIT_RETRY;
>
> Why remove the check you just added?
Because I'm dumb. :)
>> +
>> + if (s->tsr_retry > 0) {
>> + /* tsr_retry > 0 implies LSR.TEMT = 0 (transmitter not empty). */
>> + if (s->lsr & UART_LSR_TEMT) {
>> + return -1;
>> + }
>> +
>> + assert(s->watch_tag == 0);
>> + s->watch_tag = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP,
>> serial_xmit, s);
>> + } else {
>> + /* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */
>> + if (!(s->lsr & UART_LSR_TEMT)) {
>> + return -1;
>
> If you're failing migration (-1) then please error_report to say why
> so when someone hits it I can immediately see why.
Ok, something like
error_report("inconsistent state in serial device");
?
Paolo
