[PATCH v2 1/4] arm64: dts: rk3399-u-boot: Delete vop assigned-clocks/rates
jagan at amarulasolutions.com
Thu Apr 2 11:37:01 CEST 2020
On Thu, Apr 2, 2020 at 2:48 PM Kever Yang <kever.yang at rock-chips.com> wrote:
> Hi Jagan,
> On 2020/3/31 下午1:59, Jagan Teki wrote:
> > On Tue, Mar 31, 2020 at 1:06 AM Mark Kettenis <mark.kettenis at xs4all.nl> wrote:
> >>> From: Jagan Teki <jagan at amarulasolutions.com>
> >>> Cc: sunil at amarulasolutions.com, u-boot at lists.denx.de,
> >>> linux-rockchip at lists.infradead.org, linux-amarula at amarulasolutions.com,
> >>> Jagan Teki <jagan at amarulasolutions.com>
> >>> Date: Mon, 30 Mar 2020 23:46:10 +0530
> >>> Content-Type: text/plain; charset=UTF-8
> >>> Linux supporting assigned-clocks for VOP on rk3399 by assuming
> >>> U-Boot not initializing it on this linux commit:
> >>> commit <617f4472bdd3> ("arm64: dts: rockchip: init rk3399 vop clock rates")
> >>> There is no specific need to initialize these assigned clock
> >>> in U-Boot as video drivers still work with default aclk and
> >>> hclk values. So, these clocks are simply not supported by rk3399
> >>> clock driver.
> >>> But, during stdio probe of vidconsole, the device probe
> >>> will try to check whether the assigned clocks on that video
> >>> console node is initialized or not? and return error if not.
> >>> So, delete these property via -u-boot dtsi as there is
> >>> no specific need in U-Boot.
> >> Deleting these properties isn't very helpful as it means the U-Boot
> >> device tree can no longer be used by the kernel. Isn't it a better
> >> idea to implement these clocks as stubs in the u-boot clock driver?
> > I did try this before sorting out these changes, seems like it
> > requires a bit more tweaking the clock wrt display code. I really
> > didn't see any use case as of now for just to print u-boot log on
> > display out, and more over this support has been broken since from
> > releases. so bypassing these nodes can be a solutions for now.
> I agree with Mark for not touch the dts first. I don't know the detail
> of display driver but:
> - The rk3399 driver use to work without touch dts from kernel;
> - the clock driver have a rk3399_vop_set_clk() which does not depends on
The existing video drivers are written based on the puma dts and those
are not inline to Linux dts files, i.e. the reason the code is pushed
I think. The rest of rk3399 dtsi files are now inline to Linux as and
display out on these are broken from last 2 releases. so my idea is to
resolve the things one-after-another like
1. Make existing video stuff work with all rk3399 (this series along
with this patch)
2. Drop this patch change and make video drivers working w/o any
explicit changes in dts like this patch does.
Since step 2, would take time, and require close testing of all boards
I would like to pick the existing stuff for the release. Mark my words
to fix the things for the next release.
More information about the U-Boot