yeahuh / rpms / qemu-kvm

Forked from rpms/qemu-kvm 2 years ago
Clone
26ba25
From 46979f6e61d0afc31be31dab797f60c4f41c3de5 Mon Sep 17 00:00:00 2001
26ba25
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
26ba25
Date: Fri, 20 Jul 2018 12:18:00 +0200
26ba25
Subject: [PATCH 255/268] hw/char/serial: retry write if EAGAIN
26ba25
MIME-Version: 1.0
26ba25
Content-Type: text/plain; charset=UTF-8
26ba25
Content-Transfer-Encoding: 8bit
26ba25
26ba25
RH-Author: Marc-André Lureau <marcandre.lureau@redhat.com>
26ba25
Message-id: <20180720121800.18952-3-marcandre.lureau@redhat.com>
26ba25
Patchwork-id: 81455
26ba25
O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH v2 2/2] hw/char/serial: retry write if EAGAIN
26ba25
Bugzilla: 1592817
26ba25
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
26ba25
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
26ba25
RH-Acked-by: John Snow <jsnow@redhat.com>
26ba25
26ba25
If the chardev returns -1 with EAGAIN errno on write(), it should try
26ba25
to send it again (EINTR is handled by the chardev itself).
26ba25
26ba25
This fixes commit 019288bf137183bf3407c9824655b753bfafc99f
26ba25
"hw/char/serial: Only retry if qemu_chr_fe_write returns 0"
26ba25
26ba25
Tested-by: Igor Mammedov <imammedo@redhat.com>
26ba25
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
26ba25
Message-Id: <20180716110755.12499-1-marcandre.lureau@redhat.com>
26ba25
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
26ba25
26ba25
(cherry picked from commit f3575af130c700cea060b51a89008a76dae22259)
26ba25
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
26ba25
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
26ba25
---
26ba25
 hw/char/serial.c | 23 ++++++++++++++---------
26ba25
 1 file changed, 14 insertions(+), 9 deletions(-)
26ba25
26ba25
diff --git a/hw/char/serial.c b/hw/char/serial.c
26ba25
index d4057bf..478f9a8 100644
26ba25
--- a/hw/char/serial.c
26ba25
+++ b/hw/char/serial.c
26ba25
@@ -262,15 +262,20 @@ static void serial_xmit(SerialState *s)
26ba25
         if (s->mcr & UART_MCR_LOOP) {
26ba25
             /* in loopback mode, say that we just received a char */
26ba25
             serial_receive1(s, &s->tsr, 1);
26ba25
-        } else if (qemu_chr_fe_write(&s->chr, &s->tsr, 1) == 0 &&
26ba25
-                   s->tsr_retry < MAX_XMIT_RETRY) {
26ba25
-            assert(s->watch_tag == 0);
26ba25
-            s->watch_tag =
26ba25
-                qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
26ba25
-                                      serial_watch_cb, s);
26ba25
-            if (s->watch_tag > 0) {
26ba25
-                s->tsr_retry++;
26ba25
-                return;
26ba25
+        } else {
26ba25
+            int rc = qemu_chr_fe_write(&s->chr, &s->tsr, 1);
26ba25
+
26ba25
+            if ((rc == 0 ||
26ba25
+                 (rc == -1 && errno == EAGAIN)) &&
26ba25
+                s->tsr_retry < MAX_XMIT_RETRY) {
26ba25
+                assert(s->watch_tag == 0);
26ba25
+                s->watch_tag =
26ba25
+                    qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
26ba25
+                                          serial_watch_cb, s);
26ba25
+                if (s->watch_tag > 0) {
26ba25
+                    s->tsr_retry++;
26ba25
+                    return;
26ba25
+                }
26ba25
             }
26ba25
         }
26ba25
         s->tsr_retry = 0;
26ba25
-- 
26ba25
1.8.3.1
26ba25