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dkim=none (message not signed) header.d=none;dmarc=fail action=oreject header.from=opensource.cirrus.com; Received-SPF: SoftFail (protection.outlook.com: domain of transitioning opensource.cirrus.com discourages use of 84.19.233.75 as permitted sender) Received: from edirelay1.ad.cirrus.com (84.19.233.75) by CO1PEPF00012E61.mail.protection.outlook.com (10.167.249.70) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9678.18 via Frontend Transport; Thu, 5 Mar 2026 09:54:38 +0000 Received: from ediswmail9.ad.cirrus.com (ediswmail9.ad.cirrus.com [198.61.86.93]) by edirelay1.ad.cirrus.com (Postfix) with ESMTPS id 2F977406540; Thu, 5 Mar 2026 09:54:36 +0000 (UTC) Received: from ediswws03.ad.cirrus.com (ediswws03.ad.cirrus.com [198.90.208.11]) by ediswmail9.ad.cirrus.com (Postfix) with ESMTPSA id 222FC820249; Thu, 5 Mar 2026 09:54:36 +0000 (UTC) Message-ID: Subject: Re: [PATCH v3 2/2] ALSA: control: add ioctl to retrieve full card components From: Maciej Strozek To: Takashi Iwai Cc: Jaroslav Kysela , Takashi Iwai , linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org, patches@opensource.cirrus.com, alsa-devel@alsa-project.org Date: Thu, 05 Mar 2026 09:54:35 +0000 In-Reply-To: <87seagx6c4.wl-tiwai@suse.de> References: <20260303145815.9930-1-mstrozek@opensource.cirrus.com> <20260303145815.9930-2-mstrozek@opensource.cirrus.com> <87seagx6c4.wl-tiwai@suse.de> Content-Type: text/plain; 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> > + unsigned int length; > > + unsigned char *components; > > +}; >=20 > And the ioctl can serve for two purposes: >=20 > - When length=3D0 is set, the kernel stores the current number of bytes > =C2=A0 and returns without copying.=C2=A0 User-space can use this mode fo= r > =C2=A0 allocating the buffer. >=20 In alsa-lib all data must be allocated beforehand, so this length=3D=3D0 query is not very useful there, it will just go into a [512] array anyway. Are there any other users that may benefit from this? --=20 Regards, Maciej