Quoting Thierry Reding (2015-01-23 01:34:10) > On Thu, Jan 22, 2015 at 12:25:46PM -0800, Stephen Boyd wrote: > > On 01/22, Thierry Reding wrote: > > > On Wed, Jan 21, 2015 at 04:16:05PM -0800, Stephen Boyd wrote: > > > > On 01/21/2015 08:13 AM, Thierry Reding wrote: > > > > > From: Thierry Reding <treding@xxxxxxxxxx> > > > > > > > > > > This new function is similar to clk_set_parent(), except that it doesn't > > > > > actually change the parent. It merely checks that the given parent clock > > > > > can be a parent for the given clock. > > > > > > > > > > A situation where this is useful is to check that a particular setup is > > > > > valid before switching to it. One specific use-case for this is atomic > > > > > modesetting in the DRM framework where setting a mode is divided into a > > > > > check phase where a given configuration is validated before applying > > > > > changes to the hardware. > > > > > > > > > > Cc: Russell King <linux@xxxxxxxxxxxxxxxx> > > > > > Cc: Mike Turquette <mturquette@xxxxxxxxxx> > > > > > Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> > > > > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> > > > > > --- > > > > > > > > Reviewed-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> > > > > > > > > This will slightly conflict with Tomeu's patches for per-user clock > > > > constraints. It would be best if we can take this through the clk tree > > > > to fix up any conflicts > > > > > > I had hoped to take this through the drm tree to resolve the build-time. > > > Another possibility would be for me to include the clk tree (or a subset > > > thereof) in my pull-request. That way you can still fix things up in the > > > clock tree if there are any conflicts with other work. We could make > > > that work two ways: this patch gets applied to the clk tree and I pull > > > it, or I provide a stable branch that I base my pull request on and that > > > branch can be pulled into the clk tree. > > > > > > Yet another alternative would be to split out the clk_has_parent() > > > change from the series and not use it for now. That way we're going to > > > miss this check, but we do that anyway currently and it will only be > > > temporary until v3.21. > > > > > > Perhaps given where we are in the release cycle the latter would make > > > the most sense for now. > > > > Ok well let's see what Mike wants to do given that he's doing all > > the patch applying right now. I'd think that we could put this > > one patch on a different branch that we can merge into clk-next > > and you can merge into the drm tree. At least that's the typical > > workflow that usually works for everyone. > > I will be sending out a pull request today, so I'm not going to include > this patch or the dependent patch. I'll pick it up again after the merge > window and see if I need to rebase it on top of Tomeu's work. I've created an immutable branch based on 3.19-rc1 with only this patch on it and I've merged that branch into the clk tree. Immutable branch: git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git clk-has-parent You can see it merged into the clk tree here: https://git.kernel.org/cgit/linux/kernel/git/clk/linux.git/commit/?h=clk-next&id=57386798f7db7f09d69f3b44fc66570e6db91bba Regards, Mike > > Thierry -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html