From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zeus03.de (zeus03.de [194.117.254.33]) (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 24136653 for ; Tue, 18 Feb 2025 10:02:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.117.254.33 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739872970; cv=none; b=BsricjGw/3T37UtpDJmlukiTlozThcVr/HfwhR5hdSTkj8nRZNzPuANrlvJr4fuz6kwnPVEDlDZmqPs363lBANfBuLo1z9F4VTLSxagozFoSN4QRz9MMg0DvD7f+sNwnB5Bs2P1J3+6Z1U8o8yutN2ID8tHsHNwgd16suXDwgUI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739872970; c=relaxed/simple; bh=6vetKfh7RFoXrrPsOICTwJZKw3RV/gvF5pqKZT0Ib54=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WPo1e+mvFGFFWXSSddoDOC/EJ7O++I7VlpSRtoBIUzGP4XWmfiMVKE7rEQSu/GCrXLpZC/YeCeJlN1q9a/OeyBkwrIEJ91gsQwmd9VgNlG3Kr4gD1mbqjS5WtmVxCZPpakuHmFko/yydWKkuPUetlBPSu0F7wLVjW402/RH0yfA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b=XsC4gIeo; arc=none smtp.client-ip=194.117.254.33 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b="XsC4gIeo" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=k1; bh=6vet Kfh7RFoXrrPsOICTwJZKw3RV/gvF5pqKZT0Ib54=; b=XsC4gIeoUOCWHpVzQGN5 /B0m4jRTxcDu8Rqv4oPcoQowpsXzze3tK/fRxVjPe7XGqlh4+OwyOzoSaUlevDpZ 481u72X/kGD48YtBdxkMTD7/t772KoPibdb78sDJWNYq91jKrXw7LpXTCWI2zP5h iZof3PS19T5U8bIolZDpqd285GwewkFj6+0CKajLk9EFRdah5GSkCQYkrzTvLz9i dx2zKHGp843ha9gmB4coJqRTr1sshK+1zKcE4jdjFtJGC9sV3pbijF9Op9JIDCU/ CAqo5xJJGbZnLnTc8xjLILDvXOLfYgDdqzW/C9hBPnQqioPPmsEQxjr/lZ4N10Ma Ng== Received: (qmail 153260 invoked from network); 18 Feb 2025 11:02:38 +0100 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 18 Feb 2025 11:02:38 +0100 X-UD-Smtp-Session: l3s3148p1@xx+fvWcuFNsujnvP Date: Tue, 18 Feb 2025 11:02:37 +0100 From: Wolfram Sang To: "Matwey V. Kornilov" Cc: linux-i2c@vger.kernel.org Subject: Re: i2c-slave-testunit over i2c-gpio bus Message-ID: Mail-Followup-To: Wolfram Sang , "Matwey V. Kornilov" , linux-i2c@vger.kernel.org References: Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="lbx+JAEoesaRQnlV" Content-Disposition: inline In-Reply-To: --lbx+JAEoesaRQnlV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline > Thanks. But isn't it possible to attach an interrupt handler to SCL > GPIO? Or do you mean that the latency for IRQ handling is too high? Way too high for most systems. I made the in-kernel sloppy GPIO logic analyzer. From that experience, even with constant polling using an isolated CPU core, you would need at least a dedicatded 300MHz core to monitor 100kHz. With interrupts, it will probably be a magnitutde more. I scrapped that idea for the above analyzer, too slow. --lbx+JAEoesaRQnlV Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAme0Wr0ACgkQFA3kzBSg KbasRBAAhgDRLiwZPUOdU8QPODVs3DUlIRGbPPoOuUO0GT/lNhs7RNAjHndrorF7 FBn79zzSl9Up2PpbCRJG+g+ZppMV8h0T5G8PPs7sHCgoozRaCkmlXCEqVd24QR6m 6T3rjuFD8ijZ5zmlnJNcOGqieDKvM6OIv7veGCwcCY5iHAEuYjiJQ82wfiRgdZX5 cOM1HgFtYGDR415QGqfQwZl4ZG84z7yhG23JserVl/YcCYKsZQapeVMDV7zuH+Q/ zQmfy39ATCXOwDa18zfhdpwzfixQwBzDSG7a8BngWEMrkGkhfvg0NvPeAdnlyIKn aZtCkgMXv5jv2v8K+8akSo+baaOV/Y4z5vbdXmYgqXqWY1p9KuV1MQe+tVX95RN+ XNuXS6PDs6HFWNCa+DYn1x1gDf03hDkZM4aRPxmlCHMD4F3V4LHUpKoKVcr77JBw zWpCOaiNg0d6zc3+TV1Apf2JIC4JB73rOIzxI6V+WgzDSSg9iVZPgmS90HyPQFIp xU+pHORguYMdKV8tKQt3S7lgFOGI4rXFCohxn/AwJZ2OLQzloBZ5ei9fTKUnvGtk k3Vb+ItuUVdC3wEyA8UBMpwlwvwKOGeQO+naXUAWGJCSrLP+nFWauZOlquErkPZW C/SkVTXZJL4a0D6ChPF6ngFVBwxVsLfu2FH/TdXBzWqX4+LxKfI= =hurP -----END PGP SIGNATURE----- --lbx+JAEoesaRQnlV--