-----Original Message----- From: dri-devel-bounces+inki.dae=samsung.com@lists.freedesktop.org [mailto:dri-devel-bounces+inki.dae=samsung.com@lists.freedesktop.org] On Behalf Of Lucas Stach Sent: Wednesday, June 19, 2013 4:59 PM To: Tomasz Figa Cc: kgene.kim@samsung.com; devicetree-discuss@lists.ozlabs.org; sw0312.kim@samsung.com; joshi@samsung.com;
dri-devel@lists.freedesktop.org;
linux-samsung-soc@vger.kernel.org; rob.herring@calxeda.com; s.nawrocki@samsung.com; grant.likely@linaro.org; Rahul Sharma Subject: Re: [PATCH 1/4] drm/exynos: rename compatible strings for hdmi subsystem
Am Mittwoch, den 19.06.2013, 09:52 +0200 schrieb Tomasz Figa:
Hi Rahul,
On Tuesday 18 of June 2013 18:19:35 Rahul Sharma wrote:
This patch renames the combatible strings for hdmi, mixer, ddc and hdmiphy. It follows the convention of using compatible string which represent the SoC in which the IP was added for the first time.
Signed-off-by: Rahul Sharma rahul.sharma@samsung.com
Documentation/devicetree/bindings/video/exynos_hdmi.txt | 6 ++++-- Documentation/devicetree/bindings/video/exynos_hdmiddc.txt | 4 ++-- Documentation/devicetree/bindings/video/exynos_hdmiphy.txt | 6 ++++-- Documentation/devicetree/bindings/video/exynos_mixer.txt | 7 +++++-- drivers/gpu/drm/exynos/exynos_ddc.c
|
2 +- drivers/gpu/drm/exynos/exynos_hdmi.c | 2 +- drivers/gpu/drm/exynos/exynos_hdmiphy.c | 4 +++- drivers/gpu/drm/exynos/exynos_mixer.c | 12 ++++++------ 8 files changed, 26 insertions(+), 17 deletions(-)
diff --git a/Documentation/devicetree/bindings/video/exynos_hdmi.txt b/Documentation/devicetree/bindings/video/exynos_hdmi.txt index 589edee..2ac01ca 100644 --- a/Documentation/devicetree/bindings/video/exynos_hdmi.txt +++ b/Documentation/devicetree/bindings/video/exynos_hdmi.txt @@ -1,7 +1,9 @@ Device-Tree bindings for drm hdmi driver
Required properties: -- compatible: value should be "samsung,exynos5-hdmi". +- compatible: value should be one among the following:
- "samsung,exynos4210-hdmi"
- "samsung,exynos4212-hdmi"
- reg: physical base address of the hdmi and length of memory mapped region.
- interrupts: interrupt number to the cpu.
@@ -15,7 +17,7 @@ Required properties: Example:
hdmi {
compatible = "samsung,exynos5-hdmi";
compatible = "samsung,exynos4212-hdmi";Sorry, but it's a NAK from me.
DeviceTree bindings are considered an ABI. This is to allow older dtbs
to
work with new kernels.
If you just change the binding this way, you break all the existing
users
of this compatible value.
In addition you are doing it in a way that breaks bisection:
- patch 1/4 breaks existing in-tree users of current compatible values,
- after patch 2 and 3 it is still broken,
- and eventually all in-tree users are fixed by patch 4 (but you can't
fix out-of-tree users).
Please do it without changing existing compatible values. Even if they
are
misleading, this is all can be described in the documentation - just
list
SoCs that can be used with each compatible value there.
Or you could just introduce the new compatible value and make all in-tree users use this, but keep the old values around and still accept them in the drivers. This way you get the goodness of the cleaner new symbols without breaking existing users. Just mark the old values as deprecated in the documentation, so no new devicetree usees them.
That's a good idea. We really need to mitigate such misleading somehow or other.
Thanks, Inki Dae
Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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