From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: PMBus and SMBUS_BLOCK with "extended" lenght Date: Fri, 31 Mar 2017 18:33:36 +0200 Message-ID: <20170331163336.4sy4br3i2o5etcoe@ninjato> References: <1490948247.3177.233.camel@kernel.crashing.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="zbke3levozltax7w" Return-path: Received: from sauhun.de ([88.99.104.3]:43614 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933368AbdCaQdk (ORCPT ); Fri, 31 Mar 2017 12:33:40 -0400 Content-Disposition: inline In-Reply-To: <1490948247.3177.233.camel@kernel.crashing.org> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Benjamin Herrenschmidt Cc: linux-i2c --zbke3levozltax7w Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, > Did anybody give thoughts to how we could support "smbus" block > transfers with a size up to 0xff ? This is an extension of smbus > that part of the PMbus protocol spec. For completeness, SMBus Spec V3 (released 2015) increased the allowed transfer size to 255 as well. >=20 > Our current code has a lot of places where I2C_SMBUS_BLOCK_MAX is > hard wired. Including down in almost all drivers. >=20 > So it would have to be an evolutionary process. >=20 > I was thinking a message flag along with a functionality bit > maybe ? I have never really scratched my head about this issue yet and don't know of any on-going activity. It is notable, though, that we export I2C_SMBUS_BLOCK_MAX to userspace, too. Regards, Wolfram --zbke3levozltax7w Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAljehN8ACgkQFA3kzBSg KbboDQ//dX6QVKSkFfUTUX7f0igIQp2NTFqAiANA9CsYmhFgymwvQqlifhQgdLtq q0jx1LLHr6YAmRq883piEUtqwMuHKP7OnNIqWsh86FkZwj/oT/VO9M9XfpTmTjtH P4QeIMnVSthiCoOlGMbpJsnduiPJHOwOHpyWxJrLvj60NuWWOhcoPEvR6i7tPrPr fcT6UzbQ3/Jk5v4LeZgQfPuHQ/YJdAUpWd1WlK0Vzkbr3u8SDJ++kJjTdhfj4LNq f/KghD7qoYHTR0CevzXEEruEH8MYHKQALQj2bAKLN3LqSbKdTGuSZ7xr7BYmK1O+ f8TORF3k3V4/YfM/Df1xROkfVMOIVggQIIj3yLwc8mbG8Y9UR4s4Nky1Dc94PHcT 4CEXhWHotapRMBfnRbW/wup1X3SEbOqw113Kldjxp3izuAqWT8hPt+Ss7Itb1id8 tUneyEJJ/0UU76m1jYRb2/RZVqWmqIftfGq7k19c7Q9AAHjG9CYw9JpTxczxc9ZN lkCnqO6y1P2QhS71A0r6aFrYm4Y/4vO/qS6A6EcBmDuF2i476eKrk7nKLp6tkY7E abSPUzEHD8JOOYHU9aKt64WxY7vtnUY/Jrv9O4VADvB/kW7l2yAltq50PEVpb+8y pN4NVxRdwvFMKwf3Sc6Nd5h9ECgmHaJJS07tbL3VfEoKOSFhTVg= =yvvY -----END PGP SIGNATURE----- --zbke3levozltax7w--