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Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices

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  Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices Christian Lamparter <chunkeey@googlemail.com> - 2017-03-27 18:20 +0200
    Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding  for SoC devices Alban <albeu@free.fr> - 2017-03-28 10:50 +0200
      Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices Christian Lamparter <chunkeey@googlemail.com> - 2017-03-28 17:10 +0200
        Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for  SoC devices Andrew Lunn <andrew@lunn.ch> - 2017-03-28 17:30 +0200
          Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices Christian Lamparter <chunkeey@googlemail.com> - 2017-03-28 18:30 +0200
            Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for  SoC devices Andrew Lunn <andrew@lunn.ch> - 2017-03-28 18:50 +0200
              Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices Christian Lamparter <chunkeey@googlemail.com> - 2017-03-28 19:20 +0200

#1609969 — Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices

On Monday, March 13, 2017 10:05:09 PM CEST Alban wrote:
> The current binding only cover PCI devices so extend it for SoC devices.
> 
> Most SoC platforms use an MTD partition for the calibration data
> instead of an EEPROM. The qca,no-eeprom property was added to allow
> loading the EEPROM content using firmware loading. This new binding
> replace this hack with NVMEM cells, so we also mark the qca,no-eeprom
> property as deprecated in case anyone ever used it.

Please don't mark "qca,no-eeprom" as deprecated then.
If some devices geniously need to rely on userspace for extracting 
and processing the calibration data, it should be stay a
optional properties.

For example: A device that can't do easily without "qca,no-eeprom" is
the AVM FRITZ!WLAN Repeater 300E. For this device, the caldata 
is stored in the flash, however for whatever reason the vendor
choose to "reverse" it. (like completely back to front, not byteswapped
or something). So an extra "unreversing step" is required. So, it would
require some sort of a special nvmem-provider-processor as an 
alternative.

> Signed-off-by: Alban <albeu@free.fr>
> ---
> diff --git a/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt b/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
> index b7396c8..61f5f6d 100644
> --- a/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
> +++ b/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
> @@ -27,16 +27,34 @@ Required properties:
>  			- 0034 for AR9462
>  			- 0036 for AR9565
>  			- 0037 for AR9485
> +		For SoC devices the compatible should be "qca,<soctype>-wmac"
> +		and one of the following fallbacks:
> +			- "qca,ar9100-wmac"
> +			- "qca,ar9330-wmac"
> +			- "qca,ar9340-wmac"
> +			- "qca,qca9550-wmac"
> +			- "qca,qca9530-wmac"
>  - reg: Address and length of the register set for the device.
>  
> +Required properties for SoC devices:
> +- interrupt-parent: phandle of the parent interrupt controller.
> +- interrupts: Interrupt specifier for the controllers interrupt.
> +
>  Optional properties:
> +- mac-address: See ethernet.txt in the parent directory
> +- local-mac-address: See ethernet.txt in the parent directory
> +- clock-names: has to be "ref"
> +- clocks: phandle of the reference clock
> +- resets: phandle of the reset line
> +- nvmem-cell-names: has to be "eeprom" and/or "address"
> +- nvmem-cells: phandle to the eeprom nvmem cell and/or to the mac address
> +		nvmem cell.
> +
> +Deprecated properties:
>  - qca,no-eeprom: Indicates that there is no physical EEPROM connected to the
>  			ath9k wireless chip (in this case the calibration /
>  			EEPROM data will be loaded from userspace using the
>  			kernel firmware loader).
> -- mac-address: See ethernet.txt in the parent directory
> -- local-mac-address: See ethernet.txt in the parent directory
> -
It sounds like you want to deprecate mac-address and local-mac-address as well.
If so you sould add this to the commit as well. From my point of view, people
mostly flat-out patched the eeprom-image if they wanted to set the mac-address.
However, this was an extra step, if nvmem does away with it, I'm completely
fine with deprecating these properties.

Thanks,
Christian

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#1610419 — Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices

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On Mon, 27 Mar 2017 18:11:15 +0200
Christian Lamparter <chunkeey@googlemail.com> wrote:

> On Monday, March 13, 2017 10:05:09 PM CEST Alban wrote:
> > The current binding only cover PCI devices so extend it for SoC devices.
> > 
> > Most SoC platforms use an MTD partition for the calibration data
> > instead of an EEPROM. The qca,no-eeprom property was added to allow
> > loading the EEPROM content using firmware loading. This new binding
> > replace this hack with NVMEM cells, so we also mark the qca,no-eeprom
> > property as deprecated in case anyone ever used it.  
> 
> Please don't mark "qca,no-eeprom" as deprecated then.
> If some devices geniously need to rely on userspace for extracting 
> and processing the calibration data, it should be stay a
> optional properties.

Deprecated just mean that it shouldn't be used for new devices. But as
it is not used by any board, misuse the firmware loading API and
firmware loader user helper are deprecated in udev, I find we could also
just drop it.

> For example: A device that can't do easily without "qca,no-eeprom" is
> the AVM FRITZ!WLAN Repeater 300E. For this device, the caldata 
> is stored in the flash, however for whatever reason the vendor
> choose to "reverse" it. (like completely back to front, not byteswapped
> or something). So an extra "unreversing step" is required. So, it would
> require some sort of a special nvmem-provider-processor as an 
> alternative.

Or just handle this special eeprom format in the ath9k driver. I doubt
that this case is so common that it would justify adding a whole new
layer to nvmem.

> > Signed-off-by: Alban <albeu@free.fr>
> > ---
> > diff --git a/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt b/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
> > index b7396c8..61f5f6d 100644
> > --- a/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
> > +++ b/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
> > @@ -27,16 +27,34 @@ Required properties:
> >  			- 0034 for AR9462
> >  			- 0036 for AR9565
> >  			- 0037 for AR9485
> > +		For SoC devices the compatible should be "qca,<soctype>-wmac"
> > +		and one of the following fallbacks:
> > +			- "qca,ar9100-wmac"
> > +			- "qca,ar9330-wmac"
> > +			- "qca,ar9340-wmac"
> > +			- "qca,qca9550-wmac"
> > +			- "qca,qca9530-wmac"
> >  - reg: Address and length of the register set for the device.
> >  
> > +Required properties for SoC devices:
> > +- interrupt-parent: phandle of the parent interrupt controller.
> > +- interrupts: Interrupt specifier for the controllers interrupt.
> > +
> >  Optional properties:
> > +- mac-address: See ethernet.txt in the parent directory
> > +- local-mac-address: See ethernet.txt in the parent directory
> > +- clock-names: has to be "ref"
> > +- clocks: phandle of the reference clock
> > +- resets: phandle of the reset line
> > +- nvmem-cell-names: has to be "eeprom" and/or "address"
> > +- nvmem-cells: phandle to the eeprom nvmem cell and/or to the mac address
> > +		nvmem cell.
> > +
> > +Deprecated properties:
> >  - qca,no-eeprom: Indicates that there is no physical EEPROM
> > connected to the ath9k wireless chip (in this case the calibration /
> >  			EEPROM data will be loaded from userspace
> > using the kernel firmware loader).
> > -- mac-address: See ethernet.txt in the parent directory
> > -- local-mac-address: See ethernet.txt in the parent directory
> > -  
> It sounds like you want to deprecate mac-address and
> local-mac-address as well. If so you sould add this to the commit as
> well. From my point of view, people mostly flat-out patched the
> eeprom-image if they wanted to set the mac-address. However, this was
> an extra step, if nvmem does away with it, I'm completely fine with
> deprecating these properties.

The produced diff is very misleading because the mac-address properties
get lumped with the other new optional  properties. But if you look
closely it just move qca,no-eeprom to the deprecated section.

Alban

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#1611075

On Tuesday, March 28, 2017 10:44:41 AM CEST Alban wrote:
> On Mon, 27 Mar 2017 18:11:15 +0200
> Christian Lamparter <chunkeey@googlemail.com> wrote:
> 
> > On Monday, March 13, 2017 10:05:09 PM CEST Alban wrote:
> > > The current binding only cover PCI devices so extend it for SoC devices.
> > > 
> > > Most SoC platforms use an MTD partition for the calibration data
> > > instead of an EEPROM. The qca,no-eeprom property was added to allow
> > > loading the EEPROM content using firmware loading. This new binding
> > > replace this hack with NVMEM cells, so we also mark the qca,no-eeprom
> > > property as deprecated in case anyone ever used it.  
> > 
> > Please don't mark "qca,no-eeprom" as deprecated then.
> > If some devices geniously need to rely on userspace for extracting 
> > and processing the calibration data, it should be stay a
> > optional properties.
> 
> Deprecated just mean that it shouldn't be used for new devices. 
> But as it is not used by any board, misuse the firmware loading API and
> firmware loader user helper are deprecated in udev, I find we could also
> just drop it.
But LEDE/OpenWRT rely on the firmware loading API more than ever and 
currently there is not a replacement for it. From what I know, Luis 
tried to replace it with his sysdata approach:

<https://lkml.org/lkml/2016/12/16/204>

however, this was disliked by Greg KH and Linus for the following reasons.
<https://lkml.org/lkml/2016/6/16/995>:

|So I absolutely abhor "changes for changes sake".
|
|If the existing code works for existing drivers, let them keep it.
|
|And if a new interface is truly more flexible, then it should be able
|to implement the old interface with no changes, so that drivers
|shouldn't need to be changed/upgraded.
|
|Then, drivers that actually _want_ new features, or that can take
|advantage of new interfaces to actually make things *simpler*, can
|choose to make those changes. But those changes should have real
|advantages.
|[...]


your nvmem approach would need to be as universal and
powerful as the "qca,no-eeprom" + userspace solutions
in order to deprecate it.
 
> > For example: A device that can't do easily without "qca,no-eeprom" is
> > the AVM FRITZ!WLAN Repeater 300E. For this device, the caldata 
> > is stored in the flash, however for whatever reason the vendor
> > choose to "reverse" it. (like completely back to front, not byteswapped
> > or something). So an extra "unreversing step" is required. So, it would
> > require some sort of a special nvmem-provider-processor as an 
> > alternative.
> 
> Or just handle this special eeprom format in the ath9k driver. I doubt
> that this case is so common that it would justify adding a whole new
> layer to nvmem.
Well, you'll have to deal with it in nvmem, if you want it to deprecate
"qca,no-eeprom".

I looked into 10-ath9k-eeprom [0] of LEDE's AR71XX target and I noticed
that quite a few devices patch the MACs of the wifi.
If you look at the code for the Airtight C-55 and C-60, Meraki MR18,
Meraki Z1, you'll notice that each one has to add a fixed value (+1,
+2, ...) to the extraced MAC-Address. So how would you replicate this,
with "nvmem-cell-names = address" without some sort of 
nvmem-provider-processor?

Also, there's another usecase of a nvmem-provider-processor. 
For example, one could be convert all the different types of
ascii-macs (Either strings like "00:11:22:33:44:55", 
"00.11.22.33..." or "00112233..." ) to their binary representation.
For AR71XX, this is mostly done by ath79_parse_ascii_mac:

https://github.com/lede-project/source/blob/master/target/linux/ar71xx/files/arch/mips/ath79/dev-eth.c#L1204

and grep lists the following devices:
mach-dgl-5500-a1.c, mach-dhp-1565-a1.c, mach-dir-505-a1.c, mach-dir-615-c1.c
mach-dir-615-i1.c, mach-dir-825-b1.c, mach-dir-825-c1.c, mach-tew-673gru.c
mach-tew-712br.c, mach-tew-732br.c, mach-tew-823dru.c

I did a quick check: All of them use the extracted MACs for ath9k
and/or ethernet.

Note: I think Ralink/MediaTek will have the same issues.

> > >  Optional properties:
> > > +- mac-address: See ethernet.txt in the parent directory
> > > +- local-mac-address: See ethernet.txt in the parent directory
> > > [...]
> > > +
> > > +Deprecated properties:
> > >  - qca,no-eeprom: Indicates that there is no physical EEPROM
> > > connected to the ath9k wireless chip (in this case the calibration /
> > >  			EEPROM data will be loaded from userspace
> > > using the kernel firmware loader).
> > > -- mac-address: See ethernet.txt in the parent directory
> > > -- local-mac-address: See ethernet.txt in the parent directory
> > > -  
> > It sounds like you want to deprecate mac-address and
> > local-mac-address as well. If so you sould add this to the commit as
> > well. From my point of view, people mostly flat-out patched the
> > eeprom-image if they wanted to set the mac-address. However, this was
> > an extra step, if nvmem does away with it, I'm completely fine with
> > deprecating these properties.
> 
> The produced diff is very misleading because the mac-address properties
> get lumped with the other new optional  properties. But if you look
> closely it just move qca,no-eeprom to the deprecated section.
Yes ok. This is the case.

Thanks,
Christian

[0] <https://github.com/lede-project/source/blob/master/target/linux/ar71xx/base-files/etc/hotplug.d/firmware/10-ath9k-eeprom#L85>

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#1611093 — Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices

> But LEDE/OpenWRT rely on the firmware loading API more than ever and 
> currently there is not a replacement for it.

....


> I looked into 10-ath9k-eeprom [0] of LEDE's AR71XX target and I noticed
> that quite a few devices patch the MACs of the wifi.
> If you look at the code for the Airtight C-55 and C-60, Meraki MR18,
> Meraki Z1, you'll notice that each one has to add a fixed value (+1,
> +2, ...) to the extraced MAC-Address. So how would you replicate this,
> with "nvmem-cell-names = address" without some sort of 
> nvmem-provider-processor?

...
 
> https://github.com/lede-project/source/blob/master/target/linux/ar71xx/files/arch/mips/ath79/dev-eth.c#L1204
> 
> and grep lists the following devices:
> mach-dgl-5500-a1.c, mach-dhp-1565-a1.c, mach-dir-505-a1.c, mach-dir-615-c1.c
> mach-dir-615-i1.c, mach-dir-825-b1.c, mach-dir-825-c1.c, mach-tew-673gru.c
> mach-tew-712br.c, mach-tew-732br.c, mach-tew-823dru.c

I would say a big part of the problem is that all of these use cases
are outside of mainline. Why should mainline support something which
is not actually used in mainline.

So i would suggest your first step is to bring some of these devices
into mainline. Once in mainline, it becomes a mainline issue, and
people will help get it solved.

       Andrew

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#1611189

On Tuesday, March 28, 2017 5:18:37 PM CEST Andrew Lunn wrote:
> > But LEDE/OpenWRT rely on the firmware loading API more than ever and 
> > currently there is not a replacement for it.
> 
> ....
> 
> 
> > I looked into 10-ath9k-eeprom [0] of LEDE's AR71XX target and I noticed
> > that quite a few devices patch the MACs of the wifi.
> > If you look at the code for the Airtight C-55 and C-60, Meraki MR18,
> > Meraki Z1, you'll notice that each one has to add a fixed value (+1,
> > +2, ...) to the extraced MAC-Address. So how would you replicate this,
> > with "nvmem-cell-names = address" without some sort of 
> > nvmem-provider-processor?
> 
> ...
>  
> > https://github.com/lede-project/source/blob/master/target/linux/ar71xx/files/arch/mips/ath79/dev-eth.c#L1204
> > 
> > and grep lists the following devices:
> > mach-dgl-5500-a1.c, mach-dhp-1565-a1.c, mach-dir-505-a1.c, mach-dir-615-c1.c
> > mach-dir-615-i1.c, mach-dir-825-b1.c, mach-dir-825-c1.c, mach-tew-673gru.c
> > mach-tew-712br.c, mach-tew-732br.c, mach-tew-823dru.c
> 
> I would say a big part of the problem is that all of these use cases
> are outside of mainline. Why should mainline support something which
> is not actually used in mainline.
> 
> So i would suggest your first step is to bring some of these devices
> into mainline. Once in mainline, it becomes a mainline issue, and
> people will help get it solved.
>
Oh, in that case you should probably go "all out" and ask on the 
LKML to remove all of the ath9k and ath10k ahb work. From what I
know all the "users" are running some sort of OpenWRT/LEDE or a 
derivative. This is because Atheros/QCA provided a SDK based on
OpenWRT.

Alban has been trying to convert the platform to device-tree
and add them to the mainline for a while now:
 
https://patchwork.kernel.org/patch/6514551/

So, you are questioning this work as well.

Thanks,
Christian

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#1611209 — Re: [PATCH 1/7] Documentation: dt: net: Update the ath9k binding for SoC devices

> Oh, in that case you should probably go "all out" and ask on the 
> LKML to remove all of the ath9k and ath10k ahb work. From what I
> know all the "users" are running some sort of OpenWRT/LEDE or a 
> derivative. This is because Atheros/QCA provided a SDK based on
> OpenWRT.
> 
> Alban has been trying to convert the platform to device-tree
> and add them to the mainline for a while now:
>  
> https://patchwork.kernel.org/patch/6514551/
> 
> So, you are questioning this work as well.

Not at all. Ralph Sennhauser has been doing a great job of getting all
the Marvell devices into Mainline, and i help as much as i can, being
one of the Marvell SoC Maintainers.

I'm just saying, get a few boards which require these facilities into
the mainline, and then you have a much stranger base to argue from.

    Andrew

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#1611232

On Tuesday, March 28, 2017 6:41:59 PM CEST Andrew Lunn wrote:
> > Oh, in that case you should probably go "all out" and ask on the 
> > LKML to remove all of the ath9k and ath10k ahb work. From what I
> > know all the "users" are running some sort of OpenWRT/LEDE or a 
> > derivative. This is because Atheros/QCA provided a SDK based on
> > OpenWRT.
> > 
> > Alban has been trying to convert the platform to device-tree
> > and add them to the mainline for a while now:
> >  
> > https://patchwork.kernel.org/patch/6514551/
> > 
> > So, you are questioning this work as well.
> 
> Not at all. Ralph Sennhauser has been doing a great job of getting all
> the Marvell devices into Mainline, and i help as much as i can, being
> one of the Marvell SoC Maintainers.
> 
> I'm just saying, get a few boards which require these facilities into
> the mainline, and then you have a much stronger base to argue from.

I was arguing not to deprecate "qca,no-eeprom" property.

based on this quote from Linus' <https://lkml.org/lkml/2016/6/16/995>:
|if a new interface is truly more flexible, then it should be able
|to implement the old interface with no changes, so that drivers
|shouldn't need to be changed/upgraded.

what stronger point to do you want?

Thanks,
Christian

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