From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m.b4.vu (m.b4.vu [203.16.231.148]) (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 0E21521B191 for ; Sat, 24 Jan 2026 16:30:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.16.231.148 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769272255; cv=none; b=dTx9cF0nT8JQPJAyH7y/IuiHSTrhRnRMcMhthA0kW8cSPo96HhJm1BXZZDdJdr+vNN2UT02ksQJaaXhOLDsFm2yUmoGtcVSzR/ER+leUkCrTYe44JbWD+WPtoesnJAD2u6atMYwcESZ/oC9ge4x2JP2kCnP0t96AeVZ+6kHtvkY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769272255; c=relaxed/simple; bh=tTK8cSUnHJOA+WFXH+rEq8dAaDkgNj/OInYTC1HPotw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ea2Ok5H7yGbup+bUI2UZERNORqO+BkND74hWHAmAFmy6/TcD15wAcG4NG22g97HIyqZ2TdFjqKANl0/eGGVlCYNFMK2SIbETVV2Zg+GTBaf0F6F7Ak1nPw3moFUCyeC8l8DCOIDwDExD1yf/1QVy+mgtAQ0eVfDWTDkXOlRXxco= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=b4.vu; spf=pass smtp.mailfrom=b4.vu; dkim=pass (2048-bit key) header.d=b4.vu header.i=@b4.vu header.b=U17mU9J5; arc=none smtp.client-ip=203.16.231.148 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=b4.vu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=b4.vu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=b4.vu header.i=@b4.vu header.b="U17mU9J5" Received: by m.b4.vu (Postfix, from userid 1000) id 7BCA8676AE25; Sun, 25 Jan 2026 02:54:07 +1030 (ACDT) DKIM-Filter: OpenDKIM Filter v2.11.0 m.b4.vu 7BCA8676AE25 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=b4.vu; s=m1; t=1769271847; bh=LV0FXqWsvaXTyUgbQZ6JQYXCgFHUm3aDQkBt3/RVgeM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=U17mU9J5YDDNNFrvbx0Nq1hW72SyeeyqvhKO/sebLzH90nJnAIDYpo3JmT0xTkJkk cbVDKRR0bdaMy9OP3eD8W5s3t1n1A3KzWGWqp1Jp4k1r5ujRr7wsaCksWzQuErB0A2 Lz1XUTuRm1meaWULuqEOnEpHjmav+Dtz1yyDvT2XyvQ+S0mb/L+cjFtQuDpsiNg0V4 XPNlDyztE0dq069LVVBNcaNGu+LdL0gCen02Ey8rxKinHlhypucm5OjMjLL4eN7Tau KPA52BK4M1I1JbJ6UjbntUFvWwGbc+1I7wUtRg3psQYczn10mjGFnCtRUw87qcwY8/ Q11CTeLLT7W2w== Date: Sun, 25 Jan 2026 02:54:07 +1030 From: "Geoffrey D. Bennett" To: Ruslan Garynin Cc: Jaroslav Kysela , Takashi Iwai , linux-sound@vger.kernel.org Subject: Re: Scarlett 16i16 4th Gen: I/O error on kernel 6.19-rc6 (works on 6.18) Message-ID: References: Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Hi Ruslan, Audio playback for Focusrite USB interfaces is handled by the generic USB audio driver (snd-usb-audio); the FCP driver I maintain only handles the control protocol (mixer, routing, etc.) over a separate USB endpoint — it's not involved in the actual audio data transfer. I've CC'd the ALSA maintainers and linux-sound list to continue the discussion there. Regards, Geoffrey. On Sat, Jan 24, 2026 at 08:56:38PM +0500, Ruslan Garynin wrote: > Hi Geoffrey, > > I found a regression affecting Scarlett 16i16 4th Gen playback on kernel > 6.19-rc6. > > Summary: > - Working: 6.18.6-zen1-1-zen > - Broken: 6.19.0-rc6-1-mainline > - Issue: I/O error on USB audio playback > - HDA/HDMI audio works fine on 6.19-rc6, so it's USB audio specific > > Test: >   systemctl --user stop pipewire pipewire-pulse wireplumber >   speaker-test -D hw:3 -c 18 -t sine -F S32_LE > > On 6.18 (works): >   0 - Front Left >   1 - Front Right >   ... >   15 - Channel 16 >   (sound plays) > > On 6.19-rc6 (fails): >   0 - Front Left >   Write error: -5,Input/output error > > Device info: >   USB ID: 1235:821b >   FCP driver loads OK: "Focusrite Control Protocol Driver ready" >   Implicit Feedback Mode: Yes >   No errors in dmesg > > /proc/asound/card3/stream0: >   Format: S32_LE >   Channels: 18 >   Endpoint: 0x01 (1 OUT) (ASYNC) >   Rates: 44100, 48000 >   Sync Endpoint: 0x81 (1 IN) >   Implicit Feedback Mode: Yes > > Note: This might get fixed on its own when mainline is updated further > before > the stable 6.19 release. I'm just reporting this in case it doesn't, so > you're > aware of a potential issue that could affect users when 6.19 changes > eventually > land in stable kernels. > > Let me know if you need any additional info or testing. > > Thanks for maintaining the Scarlett driver! > > Best regards, > Ruslan Garynin