From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Date: Tue, 26 Aug 2014 14:41:26 +0000 Subject: Re: [linux-sunxi] Re: [PATCH 4/4] simplefb: add clock handling code Message-Id: <20140826144125.GC3027@ulmo> MIME-Version: 1 Content-Type: multipart/mixed; boundary="yLVHuoLXiP9kZBkt" List-Id: References: <20140825133953.GJ4163@ulmo.nvidia.com> <53FB3E7F.4000503@redhat.com> <20140825141600.GA14763@ulmo.nvidia.com> <20140825145854.GA15297@lukather> <20140825150501.GE14763@ulmo.nvidia.com> <20140825150900.GB21020@skynet.be> <20140826075247.GC17263@ulmo> <20140826120258.GA22395@skynet.be> <20140826122112.GC641@ulmo> <20140826123357.GB22395@skynet.be> In-Reply-To: <20140826123357.GB22395@skynet.be> To: linux-arm-kernel@lists.infradead.org --yLVHuoLXiP9kZBkt Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Aug 26, 2014 at 02:33:57PM +0200, Luc Verhaegen wrote: > On Tue, Aug 26, 2014 at 02:21:16PM +0200, Thierry Reding wrote: > > On Tue, Aug 26, 2014 at 02:02:58PM +0200, Luc Verhaegen wrote: > > > On Tue, Aug 26, 2014 at 09:52:49AM +0200, Thierry Reding wrote: > > > > On Mon, Aug 25, 2014 at 05:09:00PM +0200, Luc Verhaegen wrote: > > > > > On Mon, Aug 25, 2014 at 05:05:04PM +0200, Thierry Reding wrote: > > > > > >=20 > > > > > > No. simplefb just wants to write to some memory that hardware h= as been > > > > > > set up to scan out. The platform requires that the clocks be on. > > > > >=20 > > > > > Simplefb also requires that the memory is there and is persistent= =2E Fine=20 > > > > > for discrete graphics cards, fine for rpi where most things are h= idden=20 > > > > > from the ARM core anyway, not so fine for anybody else. > > > >=20 > > > > I don't understand. This patch series isn't changing anything about= the > > > > memory aspects of the driver yet it's working for you on sunxi, isn= 't > > > > it? So it can't be all that broken. > > > >=20 > > > > Thierry > > >=20 > > > Oh, i had to go wrestle with UBoot options and reserve 8MB off the to= p,=20 > > > which the kernel never gets told about. A nice throwback to x86 IGP= =20 > > > bioses, a past i had thought i had left behind forgood. > >=20 > > Can you not use the reserved memory code (drivers/of/of_reserved_mem.c > > in the kernel)? I think that's the generally accepted way to do this > > with DT. > >=20 > > Thierry >=20 > It was mentioned to me, and I probably could do that, but this seemed=20 > even more DT wrangling from within u-boot, and it didn't seem finished=20 > yet. Plus, all of this already was way more wrangling than i bargained=20 > for, especially with the promise of "simple"-fb. Then there is the=20 > really awkward way in which one gets to define clocks outside of a=20 > dts/compiler (you've seen the code, right?), i really did not feel like= =20 > repeating something like that. It could most probably be turned into fairly generic and reusable code so that others can use it. And it would give you a way of recovering those 8 MiB of memory that you'd otherwise loose. Thierry --yLVHuoLXiP9kZBkt Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJT/JyVAAoJEN0jrNd/PrOhdHMP/0nZKX6NSkZGszIDIiAs5Za3 KJ7OHgWRH55zgSTkft+hfPXFn4+o9WrYBE2fx1x0SYti8Fv845xlskDoOAxH52SD zOngoB1e7N/N2jD8V/tcySQx0XbcXKLCFkgdap0Zt1Fs6Gu721BmbAzKYretN3S8 +dSe0Iu46pGbbvJwfa+TjnlBhXIORTqyds3XbwSv/icluCiyZP9zn2W37wx2R6Lx JeS8au7ruh5DXsC1i3CIPOohq4E5H5nbYOJQxCfhSkJAK572qoEWBge0tpZF43uE aFZiupwbxr6aEgHf+h6eNO6qXZgzJgegPkHtVcV5odb0kDeV3aDLibASVew8RQBl +K+vH7p/+89tDlzgpRNJSqxpAkWibr9mODrgT6Dd6+/4IBhcz6zhEoTeMjO065jt WrnK5wl+naitHmZdc0HFaYV8lJlYHM+ZSNEBBqDCm7w8ZoRJxW1trHBLYReJ0pEk RCo+/sF16ZebJIDt596K8Qml9p7DgzwWh98PDb9bQ1Jwm0dIzH2JcWqsWLco+Ay0 ljNxj8B60MwoMnB5ziWyNaS0eee4OhaPioirJuxtYmjFHe7dOJ+DduvzjxdEpyOp IWEGYHcuWNLIqZqGV9LgtcaK7h0GkAbQLs8Eh9rb9oSugqmZhbrdGvbDAmfyZcvZ u5VaBiMVcyyDpslXdVJD =ICqG -----END PGP SIGNATURE----- --yLVHuoLXiP9kZBkt--