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 60AD429D288; Sat, 12 Sep 2026 16:12:07 +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=1789229528; cv=none; b=pWu1kgxNZUKm+UEugz32EQUS5Cu0ZOUD12ITEb3Moc+KXDL+RztrAFAncLfh4x3k3WWqvvvnH8ypii+BFWug99qyy/Zx9GHSVxeWW0AqgZbi8rBaDsvSY8B59nSuOVYmZ1ukdwwS9G7+yCUZ7fAZf5cjUJ7UBNqDXSQAKrG6O4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789229528; c=relaxed/simple; bh=xJBzlVBmizHJNNeECOUcwsvVP/tyVWo7EPOC9ehcAQo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CpSnQ4Df9g/MDb7hEdLz6YO7wfFY8HlEnsdC2lk8cPlhkV09joTpqm8xRNlpHvrJRyFUO7Mha2YY6aSykBvRDOLvqDZ7Mr0HUaX9tkqhwCLKKXUSHTnShuP9DB9/gsxLn0KJI6Zkgjnl4JrApXgRJR6rX47WFZ0DiYfaSm/CGJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Kc/EkwxO; 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="Kc/EkwxO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4244B1F000FF; Sat, 12 Sep 2026 16:12:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789229527; bh=i6wgWMhkKz2ollWTnt3INNwNgVmcWG0V/LhjscdxpaM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Kc/EkwxOpczji7siaITrl1OMsXdI2UqFlCKA/PiWm5Z09QtkbcuTnj+L8P5TgnrD4 3DJMQ6WmCeuM+s2M4ez//PAKqZS0lnOH0QnFmGC8besBIlolGW+b6Pul7COdh5mvWi gcNLz/Gkx07TcKM0vIN+srLFbG8wPFBzW8LZ61U0= 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 6.1 0609/1191] ASoC: apple: mca: increase SERDES reset delay Date: Sat, 12 Sep 2026 08:55:37 +0200 Message-ID: <20260912065601.930157175@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065548.086904252@linuxfoundation.org> References: <20260912065548.086904252@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 6.1-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 409b3a716ccbc..b51310f2a7141 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