From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7EDBC32792 for ; Thu, 3 Oct 2019 16:04:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 985B4222CC for ; Thu, 3 Oct 2019 16:04:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118684; bh=fik+i5HOycM4aEtSccDBSMO6kukqh4PeAR2iNgi49dk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Se3xbNUltKy9QdOjyFcz1L/EnnMqW1KcEGp4e9n4qSjAZKWjPnGDtk0n5Bvk3OS40 9K861Ylds8Uf04ZtpQMQ0FA8KjhlAEJs3+EaNs1qbbCsEnv+R1x2zdf9vSzrZjJAMn Qh+3D6ru82ylFL93zj9T1TKbjvvLIMJVeZpHl8e0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732463AbfJCQEn (ORCPT ); Thu, 3 Oct 2019 12:04:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:50892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731354AbfJCQEm (ORCPT ); Thu, 3 Oct 2019 12:04:42 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 91E8B21D81; Thu, 3 Oct 2019 16:04:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118680; bh=fik+i5HOycM4aEtSccDBSMO6kukqh4PeAR2iNgi49dk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a7hRsOXDiP8/+sflkMNZLm03YA3HwJloms58S8Xe71mhlkLn4+TdZKISKy+Xi8jza qZotPSbIDEef+uA+3WgtxlhZBXs9mzbjqlrKPUddlomx5wBkWo2c7dBRbiodCq4y9F 5TXPdn7IaF8J9LLl3MFDROWqv3Zj2avE5pKld8fY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Sakamoto , Takashi Iwai Subject: [PATCH 4.9 099/129] ALSA: firewire-tascam: check intermediate state of clock status and retry Date: Thu, 3 Oct 2019 17:53:42 +0200 Message-Id: <20191003154404.620288426@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154318.081116689@linuxfoundation.org> References: <20191003154318.081116689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Takashi Sakamoto commit e1a00b5b253a4f97216b9a33199a863987075162 upstream. 2 bytes in MSB of register for clock status is zero during intermediate state after changing status of sampling clock in models of TASCAM FireWire series. The duration of this state differs depending on cases. During the state, it's better to retry reading the register for current status of the clock. In current implementation, the intermediate state is checked only when getting current sampling transmission frequency, then retry reading. This care is required for the other operations to read the register. This commit moves the codes of check and retry into helper function commonly used for operations to read the register. Fixes: e453df44f0d6 ("ALSA: firewire-tascam: add PCM functionality") Cc: # v4.4+ Signed-off-by: Takashi Sakamoto Link: https://lore.kernel.org/r/20190910135152.29800-3-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/firewire/tascam/tascam-stream.c | 42 ++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 14 deletions(-) --- a/sound/firewire/tascam/tascam-stream.c +++ b/sound/firewire/tascam/tascam-stream.c @@ -9,20 +9,37 @@ #include #include "tascam.h" +#define CLOCK_STATUS_MASK 0xffff0000 +#define CLOCK_CONFIG_MASK 0x0000ffff + #define CALLBACK_TIMEOUT 500 static int get_clock(struct snd_tscm *tscm, u32 *data) { + int trial = 0; __be32 reg; int err; - err = snd_fw_transaction(tscm->unit, TCODE_READ_QUADLET_REQUEST, - TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS, - ®, sizeof(reg), 0); - if (err >= 0) + while (trial++ < 5) { + err = snd_fw_transaction(tscm->unit, TCODE_READ_QUADLET_REQUEST, + TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS, + ®, sizeof(reg), 0); + if (err < 0) + return err; + *data = be32_to_cpu(reg); + if (*data & CLOCK_STATUS_MASK) + break; + + // In intermediate state after changing clock status. + msleep(50); + } - return err; + // Still in the intermediate state. + if (trial >= 5) + return -EAGAIN; + + return 0; } static int set_clock(struct snd_tscm *tscm, unsigned int rate, @@ -35,7 +52,7 @@ static int set_clock(struct snd_tscm *ts err = get_clock(tscm, &data); if (err < 0) return err; - data &= 0x0000ffff; + data &= CLOCK_CONFIG_MASK; if (rate > 0) { data &= 0x000000ff; @@ -80,17 +97,14 @@ static int set_clock(struct snd_tscm *ts int snd_tscm_stream_get_rate(struct snd_tscm *tscm, unsigned int *rate) { - u32 data = 0x0; - unsigned int trials = 0; + u32 data; int err; - while (data == 0x0 || trials++ < 5) { - err = get_clock(tscm, &data); - if (err < 0) - return err; + err = get_clock(tscm, &data); + if (err < 0) + return err; - data = (data & 0xff000000) >> 24; - } + data = (data & 0xff000000) >> 24; /* Check base rate. */ if ((data & 0x0f) == 0x01)