From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754072Ab2DXMkg (ORCPT ); Tue, 24 Apr 2012 08:40:36 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:59999 "EHLO opensource.wolfsonmicro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752752Ab2DXMke (ORCPT ); Tue, 24 Apr 2012 08:40:34 -0400 Date: Tue, 24 Apr 2012 13:40:31 +0100 From: Mark Brown To: Jean Delvare Cc: Laxman Dewangan , w.sang@pengutronix.de, ben-linux@fluff.org, swarren@wwwdotorg.org, olof@lixom.net, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V1 2/2] i2c: tegra: support for I2C_M_NOSTART protocol mangling Message-ID: <20120424124030.GD13747@opensource.wolfsonmicro.com> References: <1335251976-31925-1-git-send-email-ldewangan@nvidia.com> <1335251976-31925-3-git-send-email-ldewangan@nvidia.com> <20120424105557.7ac07232@endymion.delvare> <4F967089.3050004@nvidia.com> <20120424143241.0d66fd2e@endymion.delvare> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HWvPVVuAAfuRc6SZ" Content-Disposition: inline In-Reply-To: <20120424143241.0d66fd2e@endymion.delvare> X-Cookie: Beware of Bigfoot! User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HWvPVVuAAfuRc6SZ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Apr 24, 2012 at 02:32:41PM +0200, Jean Delvare wrote: > Please keep in mind that support for I2C_M_NOSTART at the bus driver > level is optional. This means that device drivers are encouraged to not > rely on it unconditionally. Originally the flag was meant to workaround Yeah, for regmap we certainly have a fallback to kmalloc() a buffer as needed in there already. Like I say it's just an optimisation. > If you want to do scatter-gather for I2C messages, I understand the > benefit and I have no objection, and I agree that I2C_M_NOSTART lets > you do that, but then: > * We should allocate a new functionality flag for it. > * We should update the documentation to reflect the two use cases. That sounds like a good plan. I'll try to get round to it if nobody beats me to it. --HWvPVVuAAfuRc6SZ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJPlp84AAoJEBus8iNuMP3dWhMP/RMauyCf8KQimGtVYPRtZ1nJ WSig+GyXQX+AQ/XB1glFzyasV9byJJCrHTZRf314y7tfVnggcEq0Ar+McfFofmCW ZV1d/9U2MlVRysASiBUgiG2BRaWY20nfXvFHw2zKeByKjYBruxX1gyWGdvVJoQkF lkdQ8CBG60lGj15YYkJRit6x19bghT2VjKiGWKnNj1sEpaFaeD9XK9PBvqmkEyJ1 8vxsS/2IFsUYSZ6/dXkMx7/ka1NBCZDeMY7vvReG6MnG27BQJpDezx/nvmKV+I7r Q9z18wMTCFw+DGN3Akqxn90eh0R6sMCheJmJ6mtaWWg3LjVFbol0Pvlk7iQCX35z hBzsXM3jeeRbvzbfE3+F2b0GAJE98C5tYHnqya7NIjfOTx3tuYsOx48ApMbDr7iP Iml8MpmiGAC1+Jj4BI6glEDTXdXCX8UJH7Zp5Xc+KFpQw+ZgHLLZoNkWHFZX/Slm /9dFCWSPnpek4yoItHlFpc5ah5gdIp8aZommb1Uv8tAh/5VV6d3jhfFB3Sb5t8Zm CzgTQsIvvOD0fwjChztBddyLx9gsmBZo8u+GTryTTzw2l9sNMurS06s6YD7Htg2T dtaXx6oQ9ZvpX7cttoDIcWgmgh5z/v3Zkt/upDvX3eVW9vl/DaRvkjGQcS6zo2qm 12ztE4SHX9gHBLu7g59r =3dCN -----END PGP SIGNATURE----- --HWvPVVuAAfuRc6SZ-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH V1 2/2] i2c: tegra: support for I2C_M_NOSTART protocol mangling Date: Tue, 24 Apr 2012 13:40:31 +0100 Message-ID: <20120424124030.GD13747@opensource.wolfsonmicro.com> References: <1335251976-31925-1-git-send-email-ldewangan@nvidia.com> <1335251976-31925-3-git-send-email-ldewangan@nvidia.com> <20120424105557.7ac07232@endymion.delvare> <4F967089.3050004@nvidia.com> <20120424143241.0d66fd2e@endymion.delvare> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HWvPVVuAAfuRc6SZ" Return-path: Content-Disposition: inline In-Reply-To: <20120424143241.0d66fd2e-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: Laxman Dewangan , w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org, olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --HWvPVVuAAfuRc6SZ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Apr 24, 2012 at 02:32:41PM +0200, Jean Delvare wrote: > Please keep in mind that support for I2C_M_NOSTART at the bus driver > level is optional. This means that device drivers are encouraged to not > rely on it unconditionally. Originally the flag was meant to workaround Yeah, for regmap we certainly have a fallback to kmalloc() a buffer as needed in there already. Like I say it's just an optimisation. > If you want to do scatter-gather for I2C messages, I understand the > benefit and I have no objection, and I agree that I2C_M_NOSTART lets > you do that, but then: > * We should allocate a new functionality flag for it. > * We should update the documentation to reflect the two use cases. That sounds like a good plan. I'll try to get round to it if nobody beats me to it. --HWvPVVuAAfuRc6SZ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJPlp84AAoJEBus8iNuMP3dWhMP/RMauyCf8KQimGtVYPRtZ1nJ WSig+GyXQX+AQ/XB1glFzyasV9byJJCrHTZRf314y7tfVnggcEq0Ar+McfFofmCW ZV1d/9U2MlVRysASiBUgiG2BRaWY20nfXvFHw2zKeByKjYBruxX1gyWGdvVJoQkF lkdQ8CBG60lGj15YYkJRit6x19bghT2VjKiGWKnNj1sEpaFaeD9XK9PBvqmkEyJ1 8vxsS/2IFsUYSZ6/dXkMx7/ka1NBCZDeMY7vvReG6MnG27BQJpDezx/nvmKV+I7r Q9z18wMTCFw+DGN3Akqxn90eh0R6sMCheJmJ6mtaWWg3LjVFbol0Pvlk7iQCX35z hBzsXM3jeeRbvzbfE3+F2b0GAJE98C5tYHnqya7NIjfOTx3tuYsOx48ApMbDr7iP Iml8MpmiGAC1+Jj4BI6glEDTXdXCX8UJH7Zp5Xc+KFpQw+ZgHLLZoNkWHFZX/Slm /9dFCWSPnpek4yoItHlFpc5ah5gdIp8aZommb1Uv8tAh/5VV6d3jhfFB3Sb5t8Zm CzgTQsIvvOD0fwjChztBddyLx9gsmBZo8u+GTryTTzw2l9sNMurS06s6YD7Htg2T dtaXx6oQ9ZvpX7cttoDIcWgmgh5z/v3Zkt/upDvX3eVW9vl/DaRvkjGQcS6zo2qm 12ztE4SHX9gHBLu7g59r =3dCN -----END PGP SIGNATURE----- --HWvPVVuAAfuRc6SZ--