From patchwork Tue Jun 20 15:35:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 9799821 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 43E63600F6 for ; Tue, 20 Jun 2017 15:36:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 23E491FFD6 for ; Tue, 20 Jun 2017 15:36:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1693E2849E; Tue, 20 Jun 2017 15:36:56 +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 3E19E1FFD6 for ; Tue, 20 Jun 2017 15:36:55 +0000 (UTC) Received: from alsa0.perex.cz (localhost [127.0.0.1]) by alsa0.perex.cz (Postfix) with ESMTP id 96826267361; Tue, 20 Jun 2017 17:36:10 +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 CB8EF26736C; Tue, 20 Jun 2017 17:36:07 +0200 (CEST) Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id D2D0826735F for ; Tue, 20 Jun 2017 17:35:28 +0200 (CEST) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 1F390AC2F; Tue, 20 Jun 2017 15:35:28 +0000 (UTC) From: Takashi Iwai To: alsa-devel@alsa-project.org Date: Tue, 20 Jun 2017 17:35:24 +0200 Message-Id: <20170620153524.28099-5-tiwai@suse.de> X-Mailer: git-send-email 2.13.1 In-Reply-To: <20170620153524.28099-1-tiwai@suse.de> References: <20170620153524.28099-1-tiwai@suse.de> Cc: Vinod Koul , "Subhransu S . Prusty" , Pierre-Louis Bossart , Takashi Sakamoto Subject: [alsa-devel] [PATCH alsa-lib 4/4] pcm: hw: Reduce redundant sync_ptr() calls 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 There are lots of places calling sync_ptr() in the PCM hw plugin, but a few of them are redundant. For example, the sync_ptr() call after snd_pcm_hw_params() can be omitted, since the possible state change will be fetched again at snd_pcm_hw_state(), and there should be no hwptr/applptr changes by that. This patch reduces such redundant sync_ptr() calls for the minor performance optimization. The other places calling sync_ptr(), especially the ones passing SNDRV_PCM_SYNC_PTR_APPL, are still likely necessary since they need to sync the status after the ioctl, so they are left as-is. Signed-off-by: Takashi Iwai --- src/pcm/pcm_hw.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c index 721b18d2bbbb..66658599a6a6 100644 --- a/src/pcm/pcm_hw.c +++ b/src/pcm/pcm_hw.c @@ -342,7 +342,7 @@ static int snd_pcm_hw_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params) params->info &= ~0xf0000000; if (pcm->tstamp_type != SND_PCM_TSTAMP_TYPE_GETTIMEOFDAY) params->info |= SND_PCM_INFO_MONOTONIC; - return sync_ptr(hw, 0); + return 0; } static void snd_pcm_hw_close_timer(snd_pcm_hw_t *hw) @@ -608,7 +608,7 @@ static int snd_pcm_hw_prepare(snd_pcm_t *pcm) SYSMSG("SNDRV_PCM_IOCTL_PREPARE failed (%i)", err); return err; } - return sync_ptr(hw, SNDRV_PCM_SYNC_PTR_APPL); + return 0; } static int snd_pcm_hw_reset(snd_pcm_t *pcm) @@ -631,7 +631,6 @@ static int snd_pcm_hw_start(snd_pcm_t *pcm) assert(pcm->stream != SND_PCM_STREAM_PLAYBACK || snd_pcm_mmap_playback_hw_avail(pcm) > 0); #endif - sync_ptr(hw, 0); if (ioctl(hw->fd, SNDRV_PCM_IOCTL_START) < 0) { err = -errno; SYSMSG("SNDRV_PCM_IOCTL_START failed (%i)", err);