From 768dddfbe60ecc3a9a920101aa755804f8a5700e Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Thu, 18 May 2017 09:21:31 +0200 Subject: [PATCH 18/18] serial: remove watch on reset RH-Author: Fam Zheng Message-id: <20170518092131.16571-19-famz@redhat.com> Patchwork-id: 75308 O-Subject: [RHEL-7.4 qemu-kvm PATCH v3 18/18] serial: remove watch on reset Bugzilla: 1451470 RH-Acked-by: Paolo Bonzini RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Eduardo Habkost From: Paolo Bonzini Otherwise, this can cause serial_xmit to be entered with LSR.TEMT=0, which is invalid and causes an assertion failure. Reported-by: Bret Ketchum Tested-by: Bret Ketchum Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Paolo Bonzini (cherry picked from commit a1df76da57aa8772a75e7c49f8e3829d07b4c46c) Signed-off-by: Fam Zheng Signed-off-by: Miroslav Rezanina --- hw/char/serial.c | 16 ++++++++++++---- include/hw/char/serial.h | 1 + 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/hw/char/serial.c b/hw/char/serial.c index 69fefb2..39de1ca 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -224,6 +224,7 @@ static gboolean serial_watch_cb(GIOChannel *chan, GIOCondition cond, void *opaque) { SerialState *s = opaque; + s->watch_tag = 0; serial_xmit(s); return FALSE; } @@ -254,10 +255,12 @@ 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) != 1) { - if (s->tsr_retry < MAX_XMIT_RETRY && - qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, - serial_watch_cb, s) > 0) { + } else if (qemu_chr_fe_write(s->chr, &s->tsr, 1) != 1 && + 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; } @@ -656,6 +659,11 @@ static void serial_reset(void *opaque) { SerialState *s = opaque; + if (s->watch_tag > 0) { + g_source_remove(s->watch_tag); + s->watch_tag = 0; + } + s->rbr = 0; s->ier = 0; s->iir = UART_IIR_NO_INT; diff --git a/include/hw/char/serial.h b/include/hw/char/serial.h index 2661f8c..19c7763 100644 --- a/include/hw/char/serial.h +++ b/include/hw/char/serial.h @@ -56,6 +56,7 @@ struct SerialState { int it_shift; int baudbase; uint32_t tsr_retry; + guint watch_tag; uint32_t wakeup; /* Time when the last byte was successfully sent out of the tsr */ -- 1.8.3.1