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* [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
@ 2014-03-13 12:32 Ulf Hansson
       [not found] ` <1394713963-18300-1-git-send-email-ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
  0 siblings, 1 reply; 8+ messages in thread
From: Ulf Hansson @ 2014-03-13 12:32 UTC (permalink / raw)
  To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r, Linus Walleij,
	Alessandro Rubini, Russell King
  Cc: devicetree-u79uwXL29TY76Z2rM5mHXA, Ulf Hansson

As the first step in preparing the mmci driver for converting to the
mmc_of_parse API, let's align to the common names of DT bindings for
the mmc/sd highspeed modes.

Signed-off-by: Ulf Hansson <ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 Documentation/devicetree/bindings/mmc/mmci.txt |    4 ----
 arch/arm/boot/dts/ste-ccu9540.dts              |    6 +++---
 arch/arm/boot/dts/ste-href.dtsi                |    8 ++++----
 arch/arm/boot/dts/ste-nomadik-stn8815.dtsi     |    4 ++--
 arch/arm/boot/dts/ste-snowball.dts             |    4 ++--
 arch/arm/boot/dts/ste-u300.dts                 |    4 ++--
 drivers/mmc/host/mmci.c                        |    4 ++--
 7 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/mmci.txt b/Documentation/devicetree/bindings/mmc/mmci.txt
index 2b584ca..0c463e0 100644
--- a/Documentation/devicetree/bindings/mmc/mmci.txt
+++ b/Documentation/devicetree/bindings/mmc/mmci.txt
@@ -9,7 +9,3 @@ by mmc.txt and the properties used by the mmci driver.
 Required properties:
 - compatible             : contains "arm,pl18x", "arm,primecell".
 - arm,primecell-periphid : contains the PrimeCell Peripheral ID.
-
-Optional properties:
-- mmc-cap-mmc-highspeed  : indicates whether MMC is high speed capable
-- mmc-cap-sd-highspeed   : indicates whether SD is high speed capable
diff --git a/arch/arm/boot/dts/ste-ccu9540.dts b/arch/arm/boot/dts/ste-ccu9540.dts
index 2295087..651c56d 100644
--- a/arch/arm/boot/dts/ste-ccu9540.dts
+++ b/arch/arm/boot/dts/ste-ccu9540.dts
@@ -38,8 +38,8 @@
 			arm,primecell-periphid = <0x10480180>;
 			max-frequency = <100000000>;
 			bus-width = <4>;
-			mmc-cap-sd-highspeed;
-			mmc-cap-mmc-highspeed;
+			cap-sd-highspeed;
+			cap-mmc-highspeed;
 			vmmc-supply = <&ab8500_ldo_aux3_reg>;
 
 			cd-gpios  = <&gpio7 6 0x4>; // 230
@@ -63,7 +63,7 @@
 			arm,primecell-periphid = <0x10480180>;
 		        max-frequency = <100000000>;
 			bus-width = <8>;
-			mmc-cap-mmc-highspeed;
+			cap-mmc-highspeed;
 			vmmc-supply = <&ab8500_ldo_aux2_reg>;
 
 			status = "okay";
diff --git a/arch/arm/boot/dts/ste-href.dtsi b/arch/arm/boot/dts/ste-href.dtsi
index 6cb9b68..a5db487 100644
--- a/arch/arm/boot/dts/ste-href.dtsi
+++ b/arch/arm/boot/dts/ste-href.dtsi
@@ -116,8 +116,8 @@
 			arm,primecell-periphid = <0x10480180>;
 			max-frequency = <100000000>;
 			bus-width = <4>;
-			mmc-cap-sd-highspeed;
-			mmc-cap-mmc-highspeed;
+			cap-sd-highspeed;
+			cap-mmc-highspeed;
 			vmmc-supply = <&ab8500_ldo_aux3_reg>;
 			vqmmc-supply = <&vmmci>;
 			pinctrl-names = "default", "sleep";
@@ -144,7 +144,7 @@
 			arm,primecell-periphid = <0x10480180>;
 			max-frequency = <100000000>;
 			bus-width = <8>;
-			mmc-cap-mmc-highspeed;
+			cap-mmc-highspeed;
 			pinctrl-names = "default", "sleep";
 			pinctrl-0 = <&sdi2_default_mode>;
 			pinctrl-1 = <&sdi2_sleep_mode>;
@@ -157,7 +157,7 @@
 			arm,primecell-periphid = <0x10480180>;
 		        max-frequency = <100000000>;
 			bus-width = <8>;
-			mmc-cap-mmc-highspeed;
+			cap-mmc-highspeed;
 			vmmc-supply = <&ab8500_ldo_aux2_reg>;
 			pinctrl-names = "default", "sleep";
 			pinctrl-0 = <&sdi4_default_mode>;
diff --git a/arch/arm/boot/dts/ste-nomadik-stn8815.dtsi b/arch/arm/boot/dts/ste-nomadik-stn8815.dtsi
index 5acc044..d316c95 100644
--- a/arch/arm/boot/dts/ste-nomadik-stn8815.dtsi
+++ b/arch/arm/boot/dts/ste-nomadik-stn8815.dtsi
@@ -840,8 +840,8 @@
 			interrupts = <22>;
 			max-frequency = <48000000>;
 			bus-width = <4>;
-			mmc-cap-mmc-highspeed;
-			mmc-cap-sd-highspeed;
+			cap-mmc-highspeed;
+			cap-sd-highspeed;
 			cd-gpios = <&gpio3 15 0x1>;
 			cd-inverted;
 			pinctrl-names = "default";
diff --git a/arch/arm/boot/dts/ste-snowball.dts b/arch/arm/boot/dts/ste-snowball.dts
index 97d5d21..4add51f 100644
--- a/arch/arm/boot/dts/ste-snowball.dts
+++ b/arch/arm/boot/dts/ste-snowball.dts
@@ -155,7 +155,7 @@
 			arm,primecell-periphid = <0x10480180>;
 			max-frequency = <100000000>;
 			bus-width = <4>;
-			mmc-cap-mmc-highspeed;
+			cap-mmc-highspeed;
 			vmmc-supply = <&ab8500_ldo_aux3_reg>;
 			vqmmc-supply = <&vmmci>;
 			pinctrl-names = "default", "sleep";
@@ -194,7 +194,7 @@
 			arm,primecell-periphid = <0x10480180>;
 		        max-frequency = <100000000>;
 			bus-width = <8>;
-			mmc-cap-mmc-highspeed;
+			cap-mmc-highspeed;
 			vmmc-supply = <&ab8500_ldo_aux2_reg>;
 			pinctrl-names = "default", "sleep";
 			pinctrl-0 = <&sdi4_default_mode>;
diff --git a/arch/arm/boot/dts/ste-u300.dts b/arch/arm/boot/dts/ste-u300.dts
index a9da480..0a839da 100644
--- a/arch/arm/boot/dts/ste-u300.dts
+++ b/arch/arm/boot/dts/ste-u300.dts
@@ -442,8 +442,8 @@
 			clock-names = "apb_pclk", "mclk";
 			max-frequency = <24000000>;
 			bus-width = <4>; // SD-card slot
-			mmc-cap-mmc-highspeed;
-			mmc-cap-sd-highspeed;
+			cap-mmc-highspeed;
+			cap-sd-highspeed;
 			cd-gpios = <&gpio 12 0x4>;
 			cd-inverted;
 			vmmc-supply = <&ab3100_ldo_g_reg>;
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index b931226..c321bb6 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1395,9 +1395,9 @@ static void mmci_dt_populate_generic_pdata(struct device_node *np,
 	if (!pdata->f_max)
 		pr_warn("%s has no 'max-frequency' property\n", np->full_name);
 
-	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
+	if (of_get_property(np, "cap-mmc-highspeed", NULL))
 		pdata->capabilities |= MMC_CAP_MMC_HIGHSPEED;
-	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
+	if (of_get_property(np, "cap-sd-highspeed", NULL))
 		pdata->capabilities |= MMC_CAP_SD_HIGHSPEED;
 
 	of_property_read_u32(np, "bus-width", &bus_width);
-- 
1.7.9.5

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^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
       [not found] ` <1394713963-18300-1-git-send-email-ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
@ 2014-03-13 17:47   ` Russell King - ARM Linux
       [not found]     ` <20140313174703.GO21483-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
  0 siblings, 1 reply; 8+ messages in thread
From: Russell King - ARM Linux @ 2014-03-13 17:47 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r, Linus Walleij,
	Alessandro Rubini, devicetree-u79uwXL29TY76Z2rM5mHXA

On Thu, Mar 13, 2014 at 01:32:43PM +0100, Ulf Hansson wrote:
> As the first step in preparing the mmci driver for converting to the
> mmc_of_parse API, let's align to the common names of DT bindings for
> the mmc/sd highspeed modes.

NAK.  These bindings have been documented as being there since March
14th 2012, and therefore need to be supported for ever by the driver.
You can _augment_ the bindings with the generic ones, and change the
DT files, but you can't remove the parsing of the old property names.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.
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To unsubscribe from this list: send the line "unsubscribe devicetree" in
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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
       [not found]     ` <20140313174703.GO21483-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
@ 2014-03-14  7:27       ` Ulf Hansson
       [not found]         ` <CAPDyKFrw092mbirDBffF6TraUoXDLh5movp_sf9PYERG88P-Qw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
  0 siblings, 1 reply; 8+ messages in thread
From: Ulf Hansson @ 2014-03-14  7:27 UTC (permalink / raw)
  To: Russell King - ARM Linux
  Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Linus Walleij, Alessandro Rubini,
	devicetree-u79uwXL29TY76Z2rM5mHXA

On 13 March 2014 18:47, Russell King - ARM Linux <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org> wrote:
> On Thu, Mar 13, 2014 at 01:32:43PM +0100, Ulf Hansson wrote:
>> As the first step in preparing the mmci driver for converting to the
>> mmc_of_parse API, let's align to the common names of DT bindings for
>> the mmc/sd highspeed modes.
>
> NAK.  These bindings have been documented as being there since March
> 14th 2012, and therefore need to be supported for ever by the driver.
> You can _augment_ the bindings with the generic ones, and change the
> DT files, but you can't remove the parsing of the old property names.

I was kind of expecting this response. :-)

So, since we made a mistake about adding these DT bindings we are now
unable to remove them, is there really no way back?

In this particular case, I am confident that it should be safe to
remove them, but I guess this is more matter of principle, right?

Kind regards
Ulf Hansson

>
> --
> FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
> improving, and getting towards what was expected from it.
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To unsubscribe from this list: send the line "unsubscribe devicetree" in
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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
       [not found]         ` <CAPDyKFrw092mbirDBffF6TraUoXDLh5movp_sf9PYERG88P-Qw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2014-03-14 10:58           ` Linus Walleij
  2014-03-17 10:01             ` Ulf Hansson
  0 siblings, 1 reply; 8+ messages in thread
From: Linus Walleij @ 2014-03-14 10:58 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Russell King - ARM Linux,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Alessandro Rubini,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

On Fri, Mar 14, 2014 at 8:27 AM, Ulf Hansson <ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> On 13 March 2014 18:47, Russell King - ARM Linux <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org> wrote:
>> On Thu, Mar 13, 2014 at 01:32:43PM +0100, Ulf Hansson wrote:
>>> As the first step in preparing the mmci driver for converting to the
>>> mmc_of_parse API, let's align to the common names of DT bindings for
>>> the mmc/sd highspeed modes.
>>
>> NAK.  These bindings have been documented as being there since March
>> 14th 2012, and therefore need to be supported for ever by the driver.
>> You can _augment_ the bindings with the generic ones, and change the
>> DT files, but you can't remove the parsing of the old property names.
>
> I was kind of expecting this response. :-)
>
> So, since we made a mistake about adding these DT bindings we are now
> unable to remove them, is there really no way back?
>
> In this particular case, I am confident that it should be safe to
> remove them, but I guess this is more matter of principle, right?

I can guarantee that there are no deployed U300, Nomadik or
Ux500 systems out there with DTBs deployed in them, and
for certain no products. At one point that was the criterion...
All setups actually use the appended device tree.

In worst case I guess mmc-cap-sd-highspeed and
mmc-cap-mmc-highspeed could be put as aliases into the
generic parser?

Yours,
Linus Walleij
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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
  2014-03-14 10:58           ` Linus Walleij
@ 2014-03-17 10:01             ` Ulf Hansson
       [not found]               ` <CAPDyKFpJDKXK7siVMnB5umv6PnYAyNmto1yq9unxDaD9BP=oBQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
  0 siblings, 1 reply; 8+ messages in thread
From: Ulf Hansson @ 2014-03-17 10:01 UTC (permalink / raw)
  To: Linus Walleij
  Cc: devicetree@vger.kernel.org, Russell King - ARM Linux,
	linux-arm-kernel@lists.infradead.org, Alessandro Rubini

On 14 March 2014 11:58, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Fri, Mar 14, 2014 at 8:27 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>> On 13 March 2014 18:47, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:
>>> On Thu, Mar 13, 2014 at 01:32:43PM +0100, Ulf Hansson wrote:
>>>> As the first step in preparing the mmci driver for converting to the
>>>> mmc_of_parse API, let's align to the common names of DT bindings for
>>>> the mmc/sd highspeed modes.
>>>
>>> NAK.  These bindings have been documented as being there since March
>>> 14th 2012, and therefore need to be supported for ever by the driver.
>>> You can _augment_ the bindings with the generic ones, and change the
>>> DT files, but you can't remove the parsing of the old property names.
>>
>> I was kind of expecting this response. :-)
>>
>> So, since we made a mistake about adding these DT bindings we are now
>> unable to remove them, is there really no way back?
>>
>> In this particular case, I am confident that it should be safe to
>> remove them, but I guess this is more matter of principle, right?
>
> I can guarantee that there are no deployed U300, Nomadik or
> Ux500 systems out there with DTBs deployed in them, and
> for certain no products. At one point that was the criterion...
> All setups actually use the appended device tree.

It sure seems like it's safe to remove them.

If you decide to accept the patch, could we queue it through ARM SOC
with your help Linus? Maybe even for 3.15 as the sooner the better!?

>
> In worst case I guess mmc-cap-sd-highspeed and
> mmc-cap-mmc-highspeed could be put as aliases into the
> generic parser?

That's an option - and maybe mark them as deprecated. Still I would
prefer if we could remove them instead.

Kind regards
Ulf Hansson

>
> Yours,
> Linus Walleij

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
       [not found]               ` <CAPDyKFpJDKXK7siVMnB5umv6PnYAyNmto1yq9unxDaD9BP=oBQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2014-03-17 14:00                 ` Linus Walleij
  2014-03-17 16:15                   ` Mark Rutland
  0 siblings, 1 reply; 8+ messages in thread
From: Linus Walleij @ 2014-03-17 14:00 UTC (permalink / raw)
  To: Ulf Hansson, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
  Cc: Russell King - ARM Linux,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Alessandro Rubini

On Mon, Mar 17, 2014 at 11:01 AM, Ulf Hansson <ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> On 14 March 2014 11:58, Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
>> On Fri, Mar 14, 2014 at 8:27 AM, Ulf Hansson <ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
>>> On 13 March 2014 18:47, Russell King - ARM Linux <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org> wrote:

>>>> NAK.  These bindings have been documented as being there since March
>>>> 14th 2012, and therefore need to be supported for ever by the driver.
>>>> You can _augment_ the bindings with the generic ones, and change the
>>>> DT files, but you can't remove the parsing of the old property names.
>>>
>>> I was kind of expecting this response. :-)
>>>
>>> So, since we made a mistake about adding these DT bindings we are now
>>> unable to remove them, is there really no way back?
>>>
>>> In this particular case, I am confident that it should be safe to
>>> remove them, but I guess this is more matter of principle, right?
>>
>> I can guarantee that there are no deployed U300, Nomadik or
>> Ux500 systems out there with DTBs deployed in them, and
>> for certain no products. At one point that was the criterion...
>> All setups actually use the appended device tree.
>
> It sure seems like it's safe to remove them.
>
> If you decide to accept the patch, could we queue it through ARM SOC
> with your help Linus? Maybe even for 3.15 as the sooner the better!?

Actually I think I would want some indication from the device tree
maintainers on this. After all they are safeguarding the DT
process.

I am however worried about the lack of response from that camp
at times, this is supposed to be a simple yes/no question :-/

DT folks??

Yours,
Linus Walleij
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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
  2014-03-17 14:00                 ` Linus Walleij
@ 2014-03-17 16:15                   ` Mark Rutland
  2014-03-18  8:23                     ` Ulf Hansson
  0 siblings, 1 reply; 8+ messages in thread
From: Mark Rutland @ 2014-03-17 16:15 UTC (permalink / raw)
  To: Linus Walleij
  Cc: devicetree@vger.kernel.org, Ulf Hansson, Russell King - ARM Linux,
	linux-arm-kernel@lists.infradead.org, Alessandro Rubini

On Mon, Mar 17, 2014 at 02:00:58PM +0000, Linus Walleij wrote:
> On Mon, Mar 17, 2014 at 11:01 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
> > On 14 March 2014 11:58, Linus Walleij <linus.walleij@linaro.org> wrote:
> >> On Fri, Mar 14, 2014 at 8:27 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
> >>> On 13 March 2014 18:47, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:
> 
> >>>> NAK.  These bindings have been documented as being there since March
> >>>> 14th 2012, and therefore need to be supported for ever by the driver.
> >>>> You can _augment_ the bindings with the generic ones, and change the
> >>>> DT files, but you can't remove the parsing of the old property names.
> >>>
> >>> I was kind of expecting this response. :-)
> >>>
> >>> So, since we made a mistake about adding these DT bindings we are now
> >>> unable to remove them, is there really no way back?
> >>>
> >>> In this particular case, I am confident that it should be safe to
> >>> remove them, but I guess this is more matter of principle, right?

Basically, yes.

Our default position is to not break existing DTBs. In general that's
beneficial, ensures stability, and keeps people in the right mindset.
Sticking to the position even where we could be a little softer is a way
of keeping people honest -- practically everyone has a binding (or
seventy) which they hate and would love to change, sticking to the rules
(even when painful) saves us from endless churn for little benefit.

In this case the binding isn't broken; it provides the information we
need, but just not with our preferred names. As Russell has pointed out,
we can support the more standard names in addition to the current ones
(which we can deprecate for new DTs). Forcibly breaking existing DTBs is
not necessary, and I'm not sure if it's worthwhile for the sake of a few
bytes.

There are bindings out there which are fundamentally broken, which are
always reliant on platform data or just don't currently work. Those are
what we need to focus on fixing to ensure long-term support.

We also need a strategy for binding deprecation, which we do not have
currently. There was talk of unstable bindings at the last mini-summit
to allow people to tinker without committing to long-term support of
bindings, but nothing seems to have happened on that front. It would be
nice to have a plan for dealing with all these vestigal bits long term.

Thanks,
Mark.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci
  2014-03-17 16:15                   ` Mark Rutland
@ 2014-03-18  8:23                     ` Ulf Hansson
  0 siblings, 0 replies; 8+ messages in thread
From: Ulf Hansson @ 2014-03-18  8:23 UTC (permalink / raw)
  To: Mark Rutland
  Cc: devicetree@vger.kernel.org, Linus Walleij,
	Russell King - ARM Linux, linux-arm-kernel@lists.infradead.org,
	Alessandro Rubini

On 17 March 2014 17:15, Mark Rutland <mark.rutland@arm.com> wrote:
> On Mon, Mar 17, 2014 at 02:00:58PM +0000, Linus Walleij wrote:
>> On Mon, Mar 17, 2014 at 11:01 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>> > On 14 March 2014 11:58, Linus Walleij <linus.walleij@linaro.org> wrote:
>> >> On Fri, Mar 14, 2014 at 8:27 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>> >>> On 13 March 2014 18:47, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote:
>>
>> >>>> NAK.  These bindings have been documented as being there since March
>> >>>> 14th 2012, and therefore need to be supported for ever by the driver.
>> >>>> You can _augment_ the bindings with the generic ones, and change the
>> >>>> DT files, but you can't remove the parsing of the old property names.
>> >>>
>> >>> I was kind of expecting this response. :-)
>> >>>
>> >>> So, since we made a mistake about adding these DT bindings we are now
>> >>> unable to remove them, is there really no way back?
>> >>>
>> >>> In this particular case, I am confident that it should be safe to
>> >>> remove them, but I guess this is more matter of principle, right?
>
> Basically, yes.
>
> Our default position is to not break existing DTBs. In general that's
> beneficial, ensures stability, and keeps people in the right mindset.
> Sticking to the position even where we could be a little softer is a way
> of keeping people honest -- practically everyone has a binding (or
> seventy) which they hate and would love to change, sticking to the rules
> (even when painful) saves us from endless churn for little benefit.
>
> In this case the binding isn't broken; it provides the information we
> need, but just not with our preferred names. As Russell has pointed out,
> we can support the more standard names in addition to the current ones
> (which we can deprecate for new DTs). Forcibly breaking existing DTBs is
> not necessary, and I'm not sure if it's worthwhile for the sake of a few
> bytes.

I get the idea, let's keep the bindings then.

>
> There are bindings out there which are fundamentally broken, which are
> always reliant on platform data or just don't currently work. Those are
> what we need to focus on fixing to ensure long-term support.
>
> We also need a strategy for binding deprecation, which we do not have
> currently. There was talk of unstable bindings at the last mini-summit
> to allow people to tinker without committing to long-term support of
> bindings, but nothing seems to have happened on that front. It would be
> nice to have a plan for dealing with all these vestigal bits long term.

I suppose adding a comment about a binding being deprecated in the
documentation - is the best we can do for now?

Thanks for your response Mark!

Kind regards
Ulf Hansson

>
> Thanks,
> Mark.

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2014-03-18  8:23 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-03-13 12:32 [PATCH] ARM: mach-ux500|nomadik|u300: Align to common DT bindings for mmci Ulf Hansson
     [not found] ` <1394713963-18300-1-git-send-email-ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2014-03-13 17:47   ` Russell King - ARM Linux
     [not found]     ` <20140313174703.GO21483-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org>
2014-03-14  7:27       ` Ulf Hansson
     [not found]         ` <CAPDyKFrw092mbirDBffF6TraUoXDLh5movp_sf9PYERG88P-Qw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-03-14 10:58           ` Linus Walleij
2014-03-17 10:01             ` Ulf Hansson
     [not found]               ` <CAPDyKFpJDKXK7siVMnB5umv6PnYAyNmto1yq9unxDaD9BP=oBQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-03-17 14:00                 ` Linus Walleij
2014-03-17 16:15                   ` Mark Rutland
2014-03-18  8:23                     ` Ulf Hansson

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