From f3575af130c700cea060b51a89008a76dae22259 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Mon, 16 Jul 2018 13:07:55 +0200 Subject: hw/char/serial: retry write if EAGAIN MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If the chardev returns -1 with EAGAIN errno on write(), it should try to send it again (EINTR is handled by the chardev itself). This fixes commit 019288bf137183bf3407c9824655b753bfafc99f "hw/char/serial: Only retry if qemu_chr_fe_write returns 0" Tested-by: Igor Mammedov Signed-off-by: Marc-André Lureau Message-Id: <20180716110755.12499-1-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini --- hw/char/serial.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'hw/char') diff --git a/hw/char/serial.c b/hw/char/serial.c index d3b75f09f6..251f40fdac 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -260,15 +260,20 @@ static void serial_xmit(SerialState *s) if (s->mcr & UART_MCR_LOOP) { /* in loopback mode, say that we just received a char */ serial_receive1(s, &s->tsr, 1); - } else if (qemu_chr_fe_write(&s->chr, &s->tsr, 1) == 0 && - s->tsr_retry < MAX_XMIT_RETRY) { - assert(s->watch_tag == 0); - s->watch_tag = - qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, - serial_watch_cb, s); - if (s->watch_tag > 0) { - s->tsr_retry++; - return; + } else { + int rc = qemu_chr_fe_write(&s->chr, &s->tsr, 1); + + if ((rc == 0 || + (rc == -1 && errno == EAGAIN)) && + s->tsr_retry < MAX_XMIT_RETRY) { + assert(s->watch_tag == 0); + s->watch_tag = + qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, + serial_watch_cb, s); + if (s->watch_tag > 0) { + s->tsr_retry++; + return; + } } } s->tsr_retry = 0; -- cgit v1.2.3