From 42d056593de4bd94bf706c0bd62d05d2aaff77bf Mon Sep 17 00:00:00 2001 From: Arun Raghavan Date: Wed, 5 Oct 2011 00:58:52 +0530 Subject: [PATCH] alsa: Make mixer error handling more robust still Instead of relying on the snd_mixer_* functions failing, we check for POLLERR and POLLNVAL first. After this, any errors in handling the mixer events are deemed fatal (that is we cause the ALSA source/sink thread to terminate). The case where POLLERR is set but POLLNVAL is not does not actually occur, but we're making this a soft failure (stop polling the mixer, but don't kill the I/O thread). If other conditions where POLLERR occurs turn up, we need to handle them explicitly. Thanks to Linus Torvalds for helping get this right. --- src/modules/alsa/alsa-mixer.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/src/modules/alsa/alsa-mixer.c b/src/modules/alsa/alsa-mixer.c index ebb3b0f..b6cf085 100644 --- a/src/modules/alsa/alsa-mixer.c +++ b/src/modules/alsa/alsa-mixer.c @@ -286,15 +286,24 @@ static int rtpoll_work_cb(pa_rtpoll_item *i) { } if (revents) { + if (revents & (POLLNVAL | POLLERR)) { + pa_log_debug("Device disconnected, stopping poll on mixer"); + goto fail; + } else if (revents & POLLERR) { + /* This shouldn't happen. */ + pa_log_error("Got a POLLERR (revents = %04x), stopping poll on mixer", revents); + goto fail; + } + err = snd_mixer_handle_events(pd->mixer); - if (PA_UNLIKELY(err == -ENODEV)) { - /* The card has been disconnected, stop polling */ - goto fail; - } else { - /* Success, or at least an error we're likely to recover from */ + if (PA_LIKELY(err >= 0)) { pa_rtpoll_item_free(i); pa_alsa_set_mixer_rtpoll(pd, pd->mixer, pd->rtpoll); + } else { + pa_log_error("Error handling mixer event: %s", pa_alsa_strerror(err)); + ret = -1; + goto fail; } } -- 2.7.4