From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH 2/5] i2c: sh_mobile: add DMA support Date: Thu, 11 Dec 2014 22:47:32 +0100 Message-ID: <20141211214732.GC21482@katana> References: <1415355104-2031-1-git-send-email-wsa@the-dreams.de> <10746939.zT8Pinqvll@avalon> <20141210142314.GB8247@katana> <2462101.Er8OZg9N24@avalon> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="dkEUBIird37B8yKS" Return-path: Content-Disposition: inline In-Reply-To: <2462101.Er8OZg9N24@avalon> Sender: linux-sh-owner@vger.kernel.org To: Laurent Pinchart Cc: Magnus Damm , Geert Uytterhoeven , Linux I2C , Linux-sh list , Simon Horman , dmaengine@vger.kernel.org List-Id: linux-i2c@vger.kernel.org --dkEUBIird37B8yKS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > > Note that the I2C drives uses subsys_initcall() for historic reasons, > > while the DMA driver uses module_init(). This is hard to revert without > > introducing potential regressions on older boards. So, the I2C DMA > > support needs to handle deferred probe definately. I am with Laurent, I > > don't see any other way, but I'd be glad to be enlightened... >=20 > While I believe that requesting the channel at transfer time is the good= =20 > solution, I think we should still try to move to module initcalls where= =20 > possible. The risk of regressions is real so proper testing is needed. My= =20 > question is, have you tried it ? I would need to test all boards using this driver to not fail booting. Usually I2C drivers are moved to subsys_initcall because they need access to something critical (PMIC, GPIOs...) early. I don't see a sane way to do that testing. Other than that, even if we move to module_init, we reduce the chance of getting a deferred probe, but we do not eliminate it... --dkEUBIird37B8yKS Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUihD0AAoJEBQN5MwUoCm2guQQAJ6hZ4BfeMG6jkDYg7oNhcQX L1YWAho5nvObgmatd9MHqzSAhYIFPyZISLca6iGfv1+gmyNdhxcbo43xs14cv/2A A4uYoxBDkxA1CmHm6zRQl5AkChkHYrjXeohTflSusYHeFOxXzILOQLkigSX6LrKB X2mmmpAYrudy3puJnKWIf533F9S41+fVZJif6gZyiCes5eNS8iYQ/CQcxGuO6KC9 roQDA5Y4bNSW9+8IT5YdyGyxO0yG7blqgrsz4yCZYnEe1QJfyghFFqh/7SORwgD3 maB4sjcJoB3d5mzlgxOWalEP7Vxsv1KsJ82X/bJj0ZizWXh/PkkYtdYDyyBuk+Gc XycpP0F2t3zJA/kUnXFtzTpdVKDZR+bSN95Pf7+w5RjxuYgYLBWQQU8iZWP6tOG3 7Cu3a7Km/4Z34AqI2pxYVtmaOu1z844KC+o6clZs2+PvTAxz1wyS4LOa4B2NQ/7X QisQRgoCr+f6100yc3+20Z0xD9cX/X6OStyAb8uu4/BSyt4Nx9kLJiS6YGFLz2ho JpplnYK369jAGXccLrztVDWOUahUW8wDxS3BefycEoJdkuyQ314EgMqualKsmk57 6gmxVFjWgCmSF2SGpcCsZDVv7Gw2CwsDw/pLNPUncYdEaYTvSulneJGz/JhH0NGJ KYKMNZEgwQMGXEEoMZOw =SoAm -----END PGP SIGNATURE----- --dkEUBIird37B8yKS--