From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793873569; b=To0Py43egisMjpCV4h601f31SbuzPmdQpr5IE1acbiH5nGYn+vW9xRzehHhKDDvzF9an eAR4UpqEyAmWaUQVQ9MsPO8nXQbK6DAvqWSFJcxTpPu+av0tZGZepkdsA0MunBMLzVLZL s1cddNkk6NMKV/r7eO2Z2WFeQ4vDFNs75wnMbsbq2GZOWMiiDKO9joKKtnDvdnkRDW3xX cxckkvTvUB3KJOOA6P0q+6gs2zIA2TTKV08mtYiHB5VYbJUqOtBTek/HLwHT4V22juZOQ 5g22GnXJDfqDsGW6uDTw5vKppTCGjcAf4ZZ19qZLVqU0of+MA7o/ctEitbqkt2B1d0g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793873569; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=uAIe0IZmGWPzIKYTvmGWwJg4d53LmxoMF8MC3vcn1kI=; b=b7R8VTViXaVWJ4wjX1SaAuxLa8FRSpLD4EenoaXMd4bo9zHYAQs2CEEcogtlnxVi5cqy Y2IkrkSj3k/qDSPx5uSmO6UiHIA0b9ti6G7/yNKpQpBRA6ifjJKPDPeCd4GVtDI/+mzSP DthqDTjSVG2TNhmZbOAduknO4EBqn+689jqvTvwAHiXRtUYeY5EpMyPjKPS4GFZ3VhNLZ H8c3CmLHd9qKa+A2UGrcdEFWkY0mk3f1NYqqNJyOQMhcDBc5SjwkBR3arlHctAacRHCXK fo3O26+WvCbi+7eQpUZkRkpkslXbURfnDOk77rT0ADmTG2W+BGxjrTuKz4cn9LKfKLg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="TA/LhVwy"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CA812606D835 for ; Thu, 5 Nov 2026 10:12:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=TA/LhVwy Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B9251F000C1; Thu, 5 Nov 2026 10:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793873568; bh=uAIe0IZmGWPzIKYTvmGWwJg4d53LmxoMF8MC3vcn1kI=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=TA/LhVwyp+j6rdp/o4dfDzZRH7Alzr64s0yYJ4B4ecgZw7d/tKvvHK7htofPPoQp5 ghMzvvElULfuoybaWPAlNY7bluhVJmmRbAOJGiYpr/iBT84zzcID4QPkWIZyyIXCKF 23BEqFCvhjGROerXpNZximq3q1sNHAiaxoPJo5P5LZDrXAmqLYPHBQqpHb5R0F56HU 5xTqS4HN1Qry0OJcXJge7Qf7kNPVHGVurXgCVjWX6XNR7elJ42XMApSwG6AObYNAHc ULnxqxNMJVKHv/T2iuv6MJdOz0kPTdnD2yoPeBwTeZrUD+/PDPDvzjk+W+M4gMXRmW +gINxnclQbKoQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2] usb: dwc3: Update nominal max votes for qcom usb Reply-To: sashiko-reviews@lists.linux.dev To: "Akash Kumar" Cc: linux-usb@vger.kernel.org In-Reply-To: <20261105100626.2003771-1-akash.kumar@oss.qualcomm.com> References: <20261105100626.2003771-1-akash.kumar@oss.qualcomm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 05 Nov 2026 10:12:48 +0000 X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Increase the nominal max USB memory bandwidth vote to let DDR scale > higher within its nominal corner, fixing glitches seen during > simultaneous USB audio use cases. >=20 > USB_MEMORY_PEAK_SS_BW is raised from 2500 MB/s to 4500 MB/s (+2000 > MB/s, ~1.8x). This ICC vote does not by itself determine DDR > frequency; the vote-to-frequency mapping is platform-specific and > comes from each target's interconnect/OPP table. On the tested > targets, the old vote kept DDR pinned at 1 GHz within the nominal > corner, even though DDR can run at 1.5 GHz (+50%) within the same > corner. At 1 GHz, glitches were observed during multiple concurrent > USB audio use cases. >=20 > Tested internally on RB3, RB4, RB8, Shikra, and other KLM targets. > With the updated vote, DDR is allowed to run at the higher nominal > frequency, and the following were measured (not merely projected): >=20 > - USB memory throughput: 125 MB/s -> 145 MB/s (+16%) > - RTD-USBC audio latency: 17.9 ms -> 16.6 ms (-7.3%) >=20 > RTD-USBC is the round-trip audio latency measured over a USB-C audio > path; lower is better. Note the +50% DDR frequency headroom does not > map linearly to the +16% throughput gain, since throughput is also > bounded by other factors along the USB/DDR path; the frequency > increase is necessary but not sufficient to explain the full gain on > its own. >=20 > Signed-off-by: Akash Kumar Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261105100626.2003= 771-1-akash.kumar@oss.qualcomm.com?part=3D1