From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= Subject: Re: [PATCH 3/3] ARM: zynq: DT: Add Ethernet phys Date: Fri, 29 Aug 2014 17:18:07 +0200 Message-ID: <540099AF.4020005@suse.de> References: <1408550219-19825-1-git-send-email-soren.brinkmann@xilinx.com> <1408550219-19825-3-git-send-email-soren.brinkmann@xilinx.com> <5a7b6f57-b6c0-4fb3-af0d-d403277c0207@BN1AFFO11FD045.protection.gbl> <53F5D8D9.7040604@suse.de> <20140825174610.GA13737@obsidianresearch.com> <53FB9AC4.8010704@gmail.com> <660fe929-1f16-4e22-8bd3-0388cd363978@BY2FFO11FD038.protection.gbl> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="L9SjPjK87rLQL0d6dcRU2bdsfjHCWwCCn" Return-path: In-Reply-To: <660fe929-1f16-4e22-8bd3-0388cd363978@BY2FFO11FD038.protection.gbl> Sender: linux-kernel-owner@vger.kernel.org To: Michal Simek , Florian Fainelli , Jason Gunthorpe Cc: =?UTF-8?B?U8O2cmVuIEJyaW5rbWFubg==?= , Mark Rutland , "devicetree@vger.kernel.org" , Russell King , Pawel Moll , Ian Campbell , "linux-kernel@vger.kernel.org" , Rob Herring , Kumar Gala , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --L9SjPjK87rLQL0d6dcRU2bdsfjHCWwCCn Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Am 29.08.2014 16:08, schrieb Michal Simek: > On 08/25/2014 10:21 PM, Florian Fainelli wrote: >> On 08/25/2014 10:46 AM, Jason Gunthorpe wrote: >>> On Fri, Aug 22, 2014 at 01:47:09PM -0700, Florian Fainelli wrote: >>> >>>>> - the ID based strings seem to be not needed since, IIUC, the core= >>>>> reads the ID from the PHY and uses it, so I just left it out not= >>>>> trying to figure out how to obtain the correct ID >>>> >>>> It is not needed, but it is one way to specify a PHY device if you d= o >>>> not know what compatible string to use instead. >>> >>> No, it is a way to specify a PHY device if the kernel can't auto prob= e >>> the Phy ID. >>> >>> Last I checked, the kernel doesn't support plain text compatible >>> strings for phys - everything is driven on the phy id, either auto >>> probed or specified in the DT. >> >> That's right. Some PHY drivers might be relying on specific compatible= >> strings though, but not the core PHY library that probes and maps a >> driver to a PHY node. >> >>> >>>>> - the marvell compatible strings are used in our vendor tree. They= >>>>> aren't used anywhere but in our vendor tree. I though keeping th= em is >>>>> nice since it identifies the PHY fully. And in case that level o= f >>>>> detail is needed at some point it is already there. >>>> >>>> And this is the recommended way to do it in case we ever need to key= a >>>> software decision based on the hardware. >>> >>> All compatible strings need to be documented. >>> >>> .. and they need to encode more information than you get from the phy= >>> id - die revsision, package option, functional options, voltage >>> codes. Etc. >>> >>> .. and they actually need to be *right* >> >> Agreed. >> >>> >>> An example: The kernel reports 88E1318S for all four chips in that >>> family, AFAIK you have to read the package marking to figure out whic= h >>> you have (it is the same die, with options switched on/off at >>> packaging time). People have already posted patches trying to >>> helpfully add a 'marvell,88E1318S' compatible string based on kernel >>> output. Except it is wrong, it isn't actually the '8S version in the >>> HW. >>> >>> Even worse, Marvell has a whole series of socket compatible phys. Jus= t >>> because the board the DT author looked at has a '318, doesn't mean >>> that every board ever made will. We've actually already been switchin= g >>> between the 318 and 318S for production depending on which has part >>> availability. >>> >>> Basically: don't try to override self-discoverable hardware in DT >>> without a really good reason. >> >> I think that's a very good point, at the very least let's use a >> compatible string that contains the full 32-bits PHY OUI. >=20 > I think resolution is: > 1. Do not use marvell,88e1518 because it is not listed anywhere > 2. Do not add ethernet-phy-idAAAA.BBBB because it breaks autodetection > if there is different phy on the board and we shouldn't restrict us in = this. > In spite of autodetection takes some time. > 3. "ethernet-phy-ieee802.3-c22" is optional that's why doesn't need to = be added > 4. Any listed compatible string has to be parsed which takes time >=20 > That's why I think make sense not to use any compatible string. > This should give us all flexibility which we want to have. Sorry, but we do need some node that we can reference via phy-handle from the gem node, don't we? In that case, is not specifying any compatible string a valid option? If you don't want to specify the IDs, then I would've assumed we need to specify the -c22 in order to have *some* compatible string in order to trigger loading of the appropriate driver module. Regards, Andreas --=20 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imend=C3=B6rffer; HRB 16746 AG N=C3=BC= rnberg --L9SjPjK87rLQL0d6dcRU2bdsfjHCWwCCn Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJUAJmyAAoJEPou0S0+fgE/btsP/1Vjwczj47L41H3pUJAAmzT4 UVJr7/EPUzSWMekRUL82SxTXJdVHzZtuu+5CMoIDva+GQpdQnCsZysAMCK0WC03H OfG1VL2A21FAjA+/67mau4uh/AcPecgGYe6Fy5lkW3hmv2ToPnAzLrOFofXrZjrG 6EmElRzwQ+pW5pRHAkXvyO47cr6/8WCfg8QMckAgpejpQQUIQWPjQ7t4Hx2NuMW6 4dxJRtf0wmvH5nG+Fzr6Pw/fyrQ1zgMETE4a7dDoILbc145t/8OnujKx5+0qqmQX mC3IequtbMBjYr+0cBal0MIptFhgQ0te6BbGg7LJF2yjMDovvNxs2hLS1OD1nObx Oi55RwgnMDgmvnFd8/c9AUk/ymHcdTOQfS8WBwhiFv6BZY/0CDb0i13CW1pxT0XA +GCu35HWdP9XCu+CTUwiRzTuwXfjwDpR05Msb0BVZ7XejUdpMe1D+CWxpYkzeuAd PSBM9MWfHerZQ26cV79AIlyvw8Eoma8NqBVV1V1bSanYAkEmU5QlWykzysNvQ0ZU UeptIarS+zlGMgAJwlmsZbC0PNLrN4v6hjjlfEmXlmIiIfy3BDv58IGrI4/o9Mxz DfhajYNrrbzlgTdRrQ9X+iaDfm62V9XmgA8PyBQmcEQx+IYDXSYHAQJoni/n4TTs uIgz/k++al6inabvRHq/ =AYo3 -----END PGP SIGNATURE----- --L9SjPjK87rLQL0d6dcRU2bdsfjHCWwCCn--