diff options
| author | Daniel P. Berrange <berrange@redhat.com> | 2016-09-06 14:56:03 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-09-13 19:09:42 +0200 |
| commit | 7983e829336f68b6df6952dd4b03493b1486fcf5 (patch) | |
| tree | c33805ada081b4e50c17c6deab795545f5384c63 /hw/char | |
| parent | b72981b910097b31f4d0b9c111a2d2cfd9ee585b (diff) | |
sclpconsolelm: remove bogus check for -EAGAIN
The write_console_data() method in sclpconsole-lm.c checks
whether the return value of qemu_chr_fe_write() has the
value of -EAGAIN and if so then increments the buffer offset
by the value of EAGAIN. Fortunately qemu_chr_fe_write() will
never return EAGAIN directly, rather it returns -1 with
errno set to EAGAIN, so this broken code path was not
reachable. The behaviour on EAGAIN was stil bad though,
causing the write_console_data() to busy_wait repeatedly
calling qemu_chr_fe_write() with no sleep between iters.
Just remove all this loop logic and replace with a call
to qemu_chr_fe_write_all().
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1473170165-540-3-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw/char')
| -rw-r--r-- | hw/char/sclpconsole-lm.c | 21 |
1 files changed, 3 insertions, 18 deletions
diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c index a22ad8d016..dbe753147b 100644 --- a/hw/char/sclpconsole-lm.c +++ b/hw/char/sclpconsole-lm.c @@ -191,9 +191,6 @@ static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr, */ static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len) { - int ret = 0; - const uint8_t *buf_offset; - SCLPConsoleLM *scon = SCLPLM_CONSOLE(event); if (!scon->chr) { @@ -201,21 +198,9 @@ static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len) return len; } - buf_offset = buf; - while (len > 0) { - ret = qemu_chr_fe_write(scon->chr, buf, len); - if (ret == 0) { - /* a pty doesn't seem to be connected - no error */ - len = 0; - } else if (ret == -EAGAIN || (ret > 0 && ret < len)) { - len -= ret; - buf_offset += ret; - } else { - len = 0; - } - } - - return ret; + /* XXX this blocks entire thread. Rewrite to use + * qemu_chr_fe_write and background I/O callbacks */ + return qemu_chr_fe_write_all(scon->chr, buf, len); } static int process_mdb(SCLPEvent *event, MDBO *mdbo) |