From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] mmc: renesas_sdhi: use extra flag for CBSY usage Date: Thu, 10 Aug 2017 10:46:58 +0200 Message-ID: <20170810084658.GC2175@katana> References: <20170809190041.1052-1-wsa+renesas@sang-engineering.com> <20170810075850.GD16647@verge.net.au> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Fig2xvG2VGoz8o/s" Return-path: Content-Disposition: inline In-Reply-To: <20170810075850.GD16647@verge.net.au> Sender: linux-renesas-soc-owner@vger.kernel.org To: Simon Horman Cc: Wolfram Sang , linux-mmc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Dirk Behme , Chris Brandt , Yoshihiro Shimoda , Lee Jones List-Id: linux-mmc@vger.kernel.org --Fig2xvG2VGoz8o/s Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 10, 2017 at 09:58:50AM +0200, Simon Horman wrote: > On Wed, Aug 09, 2017 at 09:00:41PM +0200, Wolfram Sang wrote: > > There is one SDHI instance on Gen2 which does not have the CBSY bit. > > So, turn CBSY usage into an extra flag and set it accordingly. This has > > the additional advantage that we can also set it for other incarnations > > later. >=20 > What is the run-time effect, if any, of this change? The run-time effect is that a few cycles are saved because CBSY signals ready a bit earlier than SCLKDIVEN. Though, the more important aspect is that docs explicitly say to wait for CBSY. That's why this change was requested although I don't think it will matter much in practice. > > Chris: according to the specs I have, we can enable it for RZ as well. = I'll > > send a patch for that in a minute. If you could test this on top of thi= s one, > > that would be much appreciated! Thanks. >=20 > I take it from the above you did a pass of the available documentation to > see which SoCs support this feature. If so, thanks! I don't have docs for R-Car Gen1 SDHI. But given that even Gen2 has one SDHI instance without CBSY and Gen1 is older, my educated guess is that it does not have CBSY. --Fig2xvG2VGoz8o/s Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAlmMHYIACgkQFA3kzBSg KbZKCg/8CNr/CkrksMUU/DDHU3L4vgpcRLpHXnVHFmoJzb1rS01p75CSYLGq6TwS R9sDTPHbvxfQoK/C01JC2WfKiKygtCRbS9/1vro6KgaNKNcj8cGN91f7KoKvJ8w8 +7K1DCiCrZSvJ+d2H+6NEPIhrpVqCdLuHgKvh3vySRyGeIHVni3wFT7ZrDmvzvVp 7OG7Qg8q8TjL6MkQefjzJvZhBAbhXGvYLkdEXjg+63jlQ48JEdfZmObJRsATOQ5S cJlvd5sLYtA13s3eqth960Amkynt0n+McwSJeqZA3F3A1LgB0kMWli/WLTe5ReWE pTPSGZX33KORbrJ8hQ/0vc98s0kPm0IfQLFHT7v/dGLDZIvRhr6m0izE+On8tq1/ SSgyy38p0MykwL5/CH2phy2PDyKdHHPNn1NQUyB/e6/dfHZJx1W0imBhjcB0Z3pm etsvocRE/i0QdVQ+X01UkNE5+syM86X6zGLWcnAEc7bYxGT8SDbGZPPtT0UG4WcM CwbMJ1+Gf3wZfrgo1uKg5s6FUSLZr+SiNA2vTVmjc7+6LqZrVsjq5JQOSHsybpPH ohhFgHxWJZYcfuiMh66Vybusmrx2RUujOUh+yqwvSVMZBn188oT2H5tJcNyCxf7k P3t8f9+KnMSG7oJb8aG4z+XgPJJwd5jEI3TAB6GVe40wrC6azPg= =GhaQ -----END PGP SIGNATURE----- --Fig2xvG2VGoz8o/s--