Re: [Qemu-devel] [PATCH v3 1/1] char/serial: Fix emptyness handling

[Paolo Bonzini <pbonzini@redhat.com>]

Il 28/03/2014 12:43, Don Slutz ha scritto:
> Ping.  (Since this is a bug fix, I think it can go into 2.0)
>     -Don Slutz

I think the problem is that not many people understand the 8250 device 
model.  CCing someone who hopefully does...

Paolo

> On 03/18/14 12:29, Don Slutz wrote:
>> The commit 88c1ee73d3231c74ff90bcfc084a7589670ec244
>> char/serial: Fix emptyness check
>>
>> Still causes extra NULL byte(s) to be sent.
>>
>> So if the fifo is empty, do not send an extra NULL byte.
>>
>> Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>> Signed-off-by: Don Slutz <dslutz@verizon.com>
>> ---
>> Changes V2 to v3
>>    Revert v2 changes
>>    Fix coding style issues.
>> Changes v1 to v2
>>    Do full state change on fifo8_is_empty.
>>
>>   hw/char/serial.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/char/serial.c b/hw/char/serial.c
>> index 6d3b5af..f4d167f 100644
>> --- a/hw/char/serial.c
>> +++ b/hw/char/serial.c
>> @@ -225,8 +225,10 @@ static gboolean serial_xmit(GIOChannel *chan,
>> GIOCondition cond, void *opaque)
>>         if (s->tsr_retry <= 0) {
>>           if (s->fcr & UART_FCR_FE) {
>> -            s->tsr = fifo8_is_empty(&s->xmit_fifo) ?
>> -                        0 : fifo8_pop(&s->xmit_fifo);
>> +            if (fifo8_is_empty(&s->xmit_fifo)) {
>> +                return FALSE;
>> +            }
>> +            s->tsr = fifo8_pop(&s->xmit_fifo);
>>               if (!s->xmit_fifo.num) {
>>                   s->lsr |= UART_LSR_THRE;
>>               }
>
>
>