From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E811F343893; Sat, 12 Sep 2026 07:34:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789198496; cv=none; b=S+5kIVSuHmlVJJ+eCE1Y5mFTsqQCRHqyBs+W+nXnjqHbzbKx49bm/iJYvSvJDyGGJUgqPW6O7LaPpsbVrg9fE8GTLkgb+amxeFAH5+keFfklqU+S2TBi0hsBb27BVkcEnPvC07sC+GdgzsjPYNMtjitNaEMI+Tmp8kfXptW/j3s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789198496; c=relaxed/simple; bh=HcZ+e04qVybra1LQIx2tOB0vdf9EMSFJRVl3HSmvUT4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ea6varGkb9tUxY8FYg+646vbe1TnlF4L6rmtuCspdp9ks8EJuU7X4ugpyrHpbryViJXXgpxa9reoHqb0Xuo6itjqPy+GAzs7boWAOhdXK9K/ZMdKdoIz+1HQnnlv4DPFiLaJ5gpBRku7Yid+WZY+Pkr+h4qlapa59WjCuCyjOBM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rQNBuWnC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rQNBuWnC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A38171F000FF; Sat, 12 Sep 2026 07:34:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789198494; bh=SXqFy96TCAelz5MqzbzCslzicFFh9+PLcNFR/80zLsg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rQNBuWnColawCpIn18i/Sh7n21nxuQkz8vQ5eMyzga1mZ6xWNXnx4Wrrejnn6jd21 2/XXRsF9juq4OP5iPRD1FeYyvaRwA5Fma/pf7PBdNwlQ32iWZXzvjKwPyR2UFuI2kE E517uyrlvXGmwJGNfcl0U/C7Pr9830GzrYp9ghP4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, James Calligeros , Mark Brown , Sasha Levin Subject: [PATCH 7.2 0365/1815] ASoC: apple: mca: increase SERDES reset delay Date: Sat, 12 Sep 2026 08:35:15 +0200 Message-ID: <20260912065657.470738605@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065648.999753832@linuxfoundation.org> References: <20260912065648.999753832@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Calligeros [ Upstream commit cccd721e5aab03e92234faee72b363c9ba60611c ] The SERDES clusters in this peripheral take a long time to warm up. We tried polling the reset bit until cleared, however this is not a reliable signal of readiness to be configured. Only waiting ~25 us to give the cluster a chance to settle makes it work reliably. Increase the 2 us delay to 25 us and hope we never have to do this again. Fixes: d8b3e396088d ("ASoC: apple: mca: Fix SERDES reset sequence") Signed-off-by: James Calligeros Link: https://patch.msgid.link/20260711-apple-audio-redux-v4-1-2994d87c2f24@gmail.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- sound/soc/apple/mca.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/sound/soc/apple/mca.c b/sound/soc/apple/mca.c index 492165c0e1ea9..ebe116f32661c 100644 --- a/sound/soc/apple/mca.c +++ b/sound/soc/apple/mca.c @@ -210,10 +210,10 @@ static void mca_fe_early_trigger(struct snd_pcm_substream *substream, int cmd, SERDES_STATUS_EN | SERDES_STATUS_RST, SERDES_STATUS_RST); /* - * Experiments suggest that it takes at most ~1 us - * for the bit to clear, so wait 2 us for good measure. + * The SERDES cluster needs a bit of time to reset itself + * and settle before we start poking it. This is... slow... */ - udelay(2); + udelay(25); WARN_ON(readl_relaxed(cl->base + serdes_unit + REG_SERDES_STATUS) & SERDES_STATUS_RST); mca_modify(cl, serdes_conf, SERDES_CONF_SYNC_SEL, -- 2.53.0