From patchwork Thu Mar 29 08:02:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 10314683 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3B2A560212 for ; Thu, 29 Mar 2018 08:03:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 165882A2A3 for ; Thu, 29 Mar 2018 08:03:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 14C122A298; Thu, 29 Mar 2018 08:03:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A79AD2A3F5 for ; Thu, 29 Mar 2018 08:02:22 +0000 (UTC) Received: from alsa0.perex.cz (localhost [127.0.0.1]) by alsa0.perex.cz (Postfix) with ESMTP id 36EBF26709D; Thu, 29 Mar 2018 10:02:20 +0200 (CEST) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa0.perex.cz (Postfix, from userid 1000) id CFEEA2670D7; Thu, 29 Mar 2018 10:02:17 +0200 (CEST) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 3C618266FA1 for ; Thu, 29 Mar 2018 10:02:14 +0200 (CEST) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 28513AEEE; Thu, 29 Mar 2018 08:02:14 +0000 (UTC) From: Takashi Iwai To: alsa-devel@alsa-project.org Date: Thu, 29 Mar 2018 10:02:11 +0200 Message-Id: <20180329080211.24316-1-tiwai@suse.de> X-Mailer: git-send-email 2.16.2 Cc: Timo Wischer Subject: [alsa-devel] [PATCH] pcm: ioplug: Implement proper drain behavior X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP This patch fixes the draining behavior of ioplug in the following ways: - When no draining ioplug callback is defined, implement the draining loop using snd_pcm_wait*() and sync with the drain finishes. This is equivalent with the implementation in the kernel write(). Similarly as in kernel code, for non-blocking mode, it returns immediately after setting DRAINING state. - The hw_ptr update function checks the PCM state and stops the stream if the draining finishes. - When draining ioplug callback is defined, leave the whole draining operation to it. The callback is supposed to return -EAGAIN for non-blocking case, too. - When an unexpected error happens during draining, it drops the stream, for a safety reason. Signed-off-by: Takashi Iwai --- The patch was slightly changed from the draft version. e.g. hw_ptr_update() is called at the beginning of the loop, so that it's updated for non-blocking mode, too. And, the stream is dropped in case of unexpected errors. Also, this patch requires the previous fix ("pcm: Skip avail_min check during draining"). src/pcm/pcm_ioplug.c | 76 +++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 67 insertions(+), 9 deletions(-) diff --git a/src/pcm/pcm_ioplug.c b/src/pcm/pcm_ioplug.c index 8c0ed4836365..db64853b3136 100644 --- a/src/pcm/pcm_ioplug.c +++ b/src/pcm/pcm_ioplug.c @@ -47,6 +47,11 @@ typedef struct snd_pcm_ioplug_priv { snd_htimestamp_t trigger_tstamp; } ioplug_priv_t; +static int snd_pcm_ioplug_drop(snd_pcm_t *pcm); +static int snd_pcm_ioplug_poll_descriptors_count(snd_pcm_t *pcm); +static int snd_pcm_ioplug_poll_descriptors(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int space); +static int snd_pcm_ioplug_poll_revents(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int nfds, unsigned short *revents); + /* update the hw pointer */ /* called in lock */ static void snd_pcm_ioplug_hw_ptr_update(snd_pcm_t *pcm) @@ -57,6 +62,7 @@ static void snd_pcm_ioplug_hw_ptr_update(snd_pcm_t *pcm) hw = io->data->callback->pointer(io->data); if (hw >= 0) { snd_pcm_uframes_t delta; + snd_pcm_uframes_t avail; if ((snd_pcm_uframes_t)hw >= io->last_hw) delta = hw - io->last_hw; @@ -67,9 +73,19 @@ static void snd_pcm_ioplug_hw_ptr_update(snd_pcm_t *pcm) delta = wrap_point + hw - io->last_hw; } snd_pcm_mmap_hw_forward(io->data->pcm, delta); + /* stop the stream if all samples are drained */ + if (io->data->state == SND_PCM_STATE_DRAINING) { + avail = snd_pcm_mmap_avail(pcm); + if (avail >= pcm->buffer_size) + snd_pcm_ioplug_drop(pcm); + } io->last_hw = (snd_pcm_uframes_t)hw; - } else - io->data->state = SNDRV_PCM_STATE_XRUN; + } else { + if (io->data->state == SND_PCM_STATE_DRAINING) + snd_pcm_ioplug_drop(pcm); + else + io->data->state = SNDRV_PCM_STATE_XRUN; + } } static int snd_pcm_ioplug_info(snd_pcm_t *pcm, snd_pcm_info_t *info) @@ -488,20 +504,62 @@ static int snd_pcm_ioplug_drop(snd_pcm_t *pcm) return 0; } +static int ioplug_drain_via_poll(snd_pcm_t *pcm) +{ + ioplug_priv_t *io = pcm->private_data; + + while (io->data->state == SND_PCM_STATE_DRAINING) { + snd_pcm_ioplug_hw_ptr_update(pcm); + if (io->data->state != SND_PCM_STATE_DRAINING) + break; + /* in non-blocking mode, let application to poll() by itself */ + if (io->data->nonblock) + return -EAGAIN; + if (snd_pcm_wait_nocheck(pcm, -1) < 0) + break; + } + + return 0; /* force to drop at error */ +} + /* need own locking */ static int snd_pcm_ioplug_drain(snd_pcm_t *pcm) { ioplug_priv_t *io = pcm->private_data; - int err; + int err = 0; - if (io->data->state == SND_PCM_STATE_OPEN) + snd_pcm_lock(pcm); + switch (io->data->state) { + case SND_PCM_STATE_OPEN: + case SND_PCM_STATE_DISCONNECTED: + case SND_PCM_STATE_SUSPENDED: return -EBADFD; + case SND_PCM_STATE_PREPARED: + if (pcm->stream == SND_PCM_STREAM_PLAYBACK) { + err = snd_pcm_ioplug_start(pcm); + if (err < 0) + goto unlock; + io->data->state = SND_PCM_STATE_DRAINING; + } + break; + case SND_PCM_STATE_RUNNING: + io->data->state = SND_PCM_STATE_DRAINING; + break; + } - io->data->state = SND_PCM_STATE_DRAINING; - if (io->data->callback->drain) - io->data->callback->drain(io->data); - snd_pcm_lock(pcm); - err = snd_pcm_ioplug_drop(pcm); + if (io->data->state == SND_PCM_STATE_DRAINING) { + if (io->data->callback->drain) { + snd_pcm_unlock(pcm); /* let plugin own locking */ + err = io->data->callback->drain(io->data); + snd_pcm_lock(pcm); + } else { + err = ioplug_drain_via_poll(pcm); + } + } + + unlock: + if (!err && io->data->state != SND_PCM_STATE_SETUP) + snd_pcm_ioplug_drop(pcm); snd_pcm_unlock(pcm); return err; }