[PATCH v2] net: cadence: Add architecture dependencies

[PATCH v2] net: cadence: Add architecture dependencies

[Jean Delvare]

The Cadence ethernet chipsets are only used on specific ARM
architectures. Add Kconfig dependencies so that drivers for these
chipsets are only buildable on the relevant architectures.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
---
Changes since v1:
 * Added missing dependency on AVR32, as reported by Nicolas Ferre.

 drivers/net/ethernet/cadence/Kconfig |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- linux-3.15-rc1.orig/drivers/net/ethernet/cadence/Kconfig	2014-03-31 05:40:15.000000000 +0200
+++ linux-3.15-rc1/drivers/net/ethernet/cadence/Kconfig	2014-04-14 15:36:18.141242446 +0200
@@ -4,7 +4,7 @@
 
 config NET_CADENCE
 	bool "Cadence devices"
-	depends on HAS_IOMEM
+	depends on HAS_IOMEM && (ARM || AVR32 || COMPILE_TEST)
 	default y
 	---help---
 	  If you have a network (Ethernet) card belonging to this class, say Y.
@@ -22,7 +22,7 @@ if NET_CADENCE
 
 config ARM_AT91_ETHER
 	tristate "AT91RM9200 Ethernet support"
-	depends on HAS_DMA
+	depends on HAS_DMA && (ARCH_AT91RM9200 || COMPILE_TEST)
 	select MACB
 	---help---
 	  If you wish to compile a kernel for the AT91RM9200 and enable
@@ -30,7 +30,7 @@ config ARM_AT91_ETHER
 
 config MACB
 	tristate "Cadence MACB/GEM support"
-	depends on HAS_DMA
+	depends on HAS_DMA && (PLATFORM_AT32AP || ARCH_AT91 || ARCH_PICOXCELL || ARCH_ZYNQ || COMPILE_TEST)
 	select PHYLIB
 	---help---
 	  The Cadence MACB ethernet interface is found on many Atmel AT32 and


-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2] net: cadence: Add architecture dependencies

[David Miller]

From: Jean Delvare <jdelvare@suse.de>
Date: Mon, 14 Apr 2014 15:38:49 +0200

> The Cadence ethernet chipsets are only used on specific ARM
> architectures. Add Kconfig dependencies so that drivers for these
> chipsets are only buildable on the relevant architectures.
> 
> Signed-off-by: Jean Delvare <jdelvare@suse.de>

Applied.

Re: [PATCH v2] net: cadence: Add architecture dependencies

[Mark Brown]

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On Mon, Apr 14, 2014 at 03:38:49PM +0200, Jean Delvare wrote:
> The Cadence ethernet chipsets are only used on specific ARM
> architectures. Add Kconfig dependencies so that drivers for these
> chipsets are only buildable on the relevant architectures.

Are you sure they're not used on any of the FPGA platforms like
Microblaze?  Cadence are an IP company, might be worth having a FPGA
Kconfig that architectures commonly deployed with lots of soft IPs can
select and the IPs depend on rather than building a custom list for each
IP.

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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Michal Simek]

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On 04/22/2014 10:32 PM, Mark Brown wrote:
> On Mon, Apr 14, 2014 at 03:38:49PM +0200, Jean Delvare wrote:
>> The Cadence ethernet chipsets are only used on specific ARM
>> architectures. Add Kconfig dependencies so that drivers for these
>> chipsets are only buildable on the relevant architectures.
> 
> Are you sure they're not used on any of the FPGA platforms like
> Microblaze?  Cadence are an IP company, might be worth having a FPGA
> Kconfig that architectures commonly deployed with lots of soft IPs can
> select and the IPs depend on rather than building a custom list for each
> IP.

macb driver can be used by Microblaze too.

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform



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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Jean Delvare]

Hi Mark, Michal,

On Wed, 23 Apr 2014 09:16:49 +0200, Michal Simek wrote:
> On 04/22/2014 10:32 PM, Mark Brown wrote:
> > On Mon, Apr 14, 2014 at 03:38:49PM +0200, Jean Delvare wrote:
> >> The Cadence ethernet chipsets are only used on specific ARM
> >> architectures. Add Kconfig dependencies so that drivers for these
> >> chipsets are only buildable on the relevant architectures.
> > 
> > Are you sure they're not used on any of the FPGA platforms like
> > Microblaze?

I'm not sure of anything, embedded isn't my area.

> > Cadence are an IP company,

I can't parse this, sorry. What is an "IP company"?

> > might be worth having a FPGA
> > Kconfig that architectures commonly deployed with lots of soft IPs can
> > select and the IPs depend on rather than building a custom list for each
> > IP.

What are "soft IPs"? I'm afraid I wouldn't be able to translate your
proposal into a patch, I just don't understand what you mean exactly.

> macb driver can be used by Microblaze too.

Thanks for the information. I will send a patch adding MICROBLAZE to
the dependencies. Out of curiosity, is there any way I could have found
out by myself?

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2] net: cadence: Add architecture dependencies

[Michal Simek]

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On 04/23/2014 09:40 AM, Jean Delvare wrote:
> Hi Mark, Michal,
> 
> On Wed, 23 Apr 2014 09:16:49 +0200, Michal Simek wrote:
>> On 04/22/2014 10:32 PM, Mark Brown wrote:
>>> On Mon, Apr 14, 2014 at 03:38:49PM +0200, Jean Delvare wrote:
>>>> The Cadence ethernet chipsets are only used on specific ARM
>>>> architectures. Add Kconfig dependencies so that drivers for these
>>>> chipsets are only buildable on the relevant architectures.
>>>
>>> Are you sure they're not used on any of the FPGA platforms like
>>> Microblaze?
> 
> I'm not sure of anything, embedded isn't my area.
> 
>>> Cadence are an IP company,
> 
> I can't parse this, sorry. What is an "IP company"?

Company which is creating this piece of HW which is called IP.


>>> might be worth having a FPGA
>>> Kconfig that architectures commonly deployed with lots of soft IPs can
>>> select and the IPs depend on rather than building a custom list for each
>>> IP.
> 
> What are "soft IPs"? I'm afraid I wouldn't be able to translate your
> proposal into a patch, I just don't understand what you mean exactly.

Microblaze is soft-core cpu or soft IP if you like. It means it is written
in VHDL/Verilog or in different hardware description language.

>> macb driver can be used by Microblaze too.
> 
> Thanks for the information. I will send a patch adding MICROBLAZE to
> the dependencies. Out of curiosity, is there any way I could have found
> out by myself?

Microblaze doesn't need to be only one. I am not sure if there is
any AXI bridge for openrisc.
IMHO you should just add COMPILE_TEST and do not try to extend that
list of dependencies.

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform



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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Jean Delvare]

Hi Michal,

On Wed, 23 Apr 2014 11:35:55 +0200, Michal Simek wrote:
> On 04/23/2014 09:40 AM, Jean Delvare wrote:
> > Thanks for the information. I will send a patch adding MICROBLAZE to
> > the dependencies. Out of curiosity, is there any way I could have found
> > out by myself?
> 
> Microblaze doesn't need to be only one. I am not sure if there is
> any AXI bridge for openrisc.

You lost me here again :-(

> IMHO you should just add COMPILE_TEST and do not try to extend that
> list of dependencies.

COMPILE_TEST is already present, I can't add it twice ;-) But
COMPILE_TEST isn't supposed to be used when the architecture /
platform / system is actually expected to possibly need the driver in
question. If the list of possible hardware dependencies isn't well
known, or is too complex to express, or too difficult to maintain, then
we have to either make it broader, or even drop it.

Originally I wanted to hide the Cadence drivers from X86 kernel
configuration. If there's still a way to achieve that, let's do it. If
not, we can leave the hardware dependency for ARM_AT91_ETHER and drop
the one for MACB (and subsequently NET_CADENCE.) That's still better
than nothing.

Please let me know how you want to proceed.

Thanks,
-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2] net: cadence: Add architecture dependencies

[Michal Simek]

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Hi Jean,

On 04/23/2014 12:48 PM, Jean Delvare wrote:
> Hi Michal,
> 
> On Wed, 23 Apr 2014 11:35:55 +0200, Michal Simek wrote:
>> On 04/23/2014 09:40 AM, Jean Delvare wrote:
>>> Thanks for the information. I will send a patch adding MICROBLAZE to
>>> the dependencies. Out of curiosity, is there any way I could have found
>>> out by myself?
>>
>> Microblaze doesn't need to be only one. I am not sure if there is
>> any AXI bridge for openrisc.
> 
> You lost me here again :-(

at least on Zynq we have cadence macb on AXI bus. Not sure which bus
is used on Atmel. SoC vendor just buy it from Cadence and add it to
silicon.
Or for microblaze case because it is soft-core we can simple
connect Microblaze with this IP.
It means if you have any soft-core cpu which supports AXI bus
or bridge to AXI it can connect this IP.

>> IMHO you should just add COMPILE_TEST and do not try to extend that
>> list of dependencies.
> 
> COMPILE_TEST is already present, I can't add it twice ;-) But
> COMPILE_TEST isn't supposed to be used when the architecture /
> platform / system is actually expected to possibly need the driver in
> question. If the list of possible hardware dependencies isn't well
> known, or is too complex to express, or too difficult to maintain, then
> we have to either make it broader, or even drop it.

I am not COMPILE_TEST expert but IMHO idea was to compile all drivers
for all platforms and do not hide anything. Even I think that will
be just easier not to use COMPILE_TEST at all because it is just pain.
At least I use zero-day testing system to compile it for others architectures.
And I have asked Fengguang to explicitly enable COMPILE_TEST for all platforms
and do not depend that randconfig enables it.

> Originally I wanted to hide the Cadence drivers from X86 kernel
> configuration. If there's still a way to achieve that, let's do it. If
> not, we can leave the hardware dependency for ARM_AT91_ETHER and drop
> the one for MACB (and subsequently NET_CADENCE.) That's still better
> than nothing.

Any reason to hide this driver for x86?

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform



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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Mark Brown]

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On Wed, Apr 23, 2014 at 01:14:41PM +0200, Michal Simek wrote:
> On 04/23/2014 12:48 PM, Jean Delvare wrote:

> > Originally I wanted to hide the Cadence drivers from X86 kernel
> > configuration. If there's still a way to achieve that, let's do it. If
> > not, we can leave the hardware dependency for ARM_AT91_ETHER and drop
> > the one for MACB (and subsequently NET_CADENCE.) That's still better
> > than nothing.

> Any reason to hide this driver for x86?

Distro maintainers like Jean are complaining about build times for their
kernels if they enable absolutely everything so if they're never likely
to see any hardware using something they want to skip it.

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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Michal Simek]

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On 04/23/2014 01:34 PM, Mark Brown wrote:
> On Wed, Apr 23, 2014 at 01:14:41PM +0200, Michal Simek wrote:
>> On 04/23/2014 12:48 PM, Jean Delvare wrote:
> 
>>> Originally I wanted to hide the Cadence drivers from X86 kernel
>>> configuration. If there's still a way to achieve that, let's do it. If
>>> not, we can leave the hardware dependency for ARM_AT91_ETHER and drop
>>> the one for MACB (and subsequently NET_CADENCE.) That's still better
>>> than nothing.
> 
>> Any reason to hide this driver for x86?
> 
> Distro maintainers like Jean are complaining about build times for their
> kernels if they enable absolutely everything so if they're never likely
> to see any hardware using something they want to skip it.

Is there any reasonable solution for this?
1. One group is saying use COMPILE_TEST for every driver to have better
coverage.
2. Next group is saying I don't want to build everything for my arch.

Fixing Kconfig to say !x86 is probably not the right way to go.

Isn't it enough not to enable absolutely everything?

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform



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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Jean Delvare]

Hi Michal,

On Wed, 23 Apr 2014 15:16:04 +0200, Michal Simek wrote:
> On 04/23/2014 01:34 PM, Mark Brown wrote:
> > On Wed, Apr 23, 2014 at 01:14:41PM +0200, Michal Simek wrote:
> >> Any reason to hide this driver for x86?
> > 
> > Distro maintainers like Jean are complaining about build times for their
> > kernels if they enable absolutely everything so if they're never likely
> > to see any hardware using something they want to skip it.

Exactly. See this discussion thread for details:
  https://lkml.org/lkml/2014/4/14/280

> Is there any reasonable solution for this?
> 1. One group is saying use COMPILE_TEST for every driver to have better
> coverage.

I think pretty much everyone agrees with this. The problem is that
COMPILE_TEST is relatively new so a lot of old drivers don't have it
yet, and developers and maintainers are not yet used to using it or
asking for it.

> 2. Next group is saying I don't want to build everything for my arch.

I don't understand what you mean here.

The idea is that distro maintainers or simple users don't set
COMPILE_TEST so they only see what is useful to them, while developers
set COMPILE_TEST to be able to build-test everything.

Before COMPILE_TEST was introduced, it wasn't possible to make everyone
happy. Now it is, so let's just do it.

> Fixing Kconfig to say !x86 is probably not the right way to go.

Definitely not. I did not even consider it as an acceptable workaround.
If we can't come up with reasonable dependencies for a given driver, we
can just leave it as is. There's plenty of easier drivers to work on :)

> Isn't it enough not to enable absolutely everything?

Everything that is visible requires everyone around to make a decision.
The more we can help them, the easier the process.

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH v2] net: cadence: Add architecture dependencies

[Mark Brown]

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On Wed, Apr 23, 2014 at 03:16:04PM +0200, Michal Simek wrote:
> On 04/23/2014 01:34 PM, Mark Brown wrote:

> > Distro maintainers like Jean are complaining about build times for their
> > kernels if they enable absolutely everything so if they're never likely
> > to see any hardware using something they want to skip it.

> Is there any reasonable solution for this?
> 1. One group is saying use COMPILE_TEST for every driver to have better
> coverage.
> 2. Next group is saying I don't want to build everything for my arch.

> Fixing Kconfig to say !x86 is probably not the right way to go.

> Isn't it enough not to enable absolutely everything?

You're misunderstanding - the discussion here is for the !COMPILE_TEST
case.  Nobody wants to hide things in the COMPILE_TEST case, it's about
what happens when that's disabled for production kernels.

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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Mark Brown]

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On Wed, Apr 23, 2014 at 12:48:38PM +0200, Jean Delvare wrote:
> On Wed, 23 Apr 2014 11:35:55 +0200, Michal Simek wrote:
> > On 04/23/2014 09:40 AM, Jean Delvare wrote:

> > > Thanks for the information. I will send a patch adding MICROBLAZE to
> > > the dependencies. Out of curiosity, is there any way I could have found
> > > out by myself?

> > Microblaze doesn't need to be only one. I am not sure if there is
> > any AXI bridge for openrisc.

> You lost me here again :-(

AXI is a bus commonly used inside ICs, it's one of a series of buses of
varying complexity commonly used to integrate IPs into chips.  Michal is
wondering if there is anything available to interface an AXI bus to an
OpenRISC processor.

> > IMHO you should just add COMPILE_TEST and do not try to extend that
> > list of dependencies.

> COMPILE_TEST is already present, I can't add it twice ;-) But
> COMPILE_TEST isn't supposed to be used when the architecture /
> platform / system is actually expected to possibly need the driver in
> question. If the list of possible hardware dependencies isn't well
> known, or is too complex to express, or too difficult to maintain, then
> we have to either make it broader, or even drop it.

Like I said in my original reply for things like this that are clearly
generic IPs not tied to a particular chip vendor I think we ought to at
least create a symbol they can depend on which can be selected by the
architectures that are commonly deployed with FPGAs (or just in custom
silicon like ARM).  That will cover most of the uses I expect.

For some of these IPs there will also be additional places where they
could appear (eg, if something gets put on a PCI card) but they should
be much less common.

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Re: [PATCH v2] net: cadence: Add architecture dependencies

[Mark Brown]

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On Wed, Apr 23, 2014 at 09:40:10AM +0200, Jean Delvare wrote:
> On Wed, 23 Apr 2014 09:16:49 +0200, Michal Simek wrote:

> > > Cadence are an IP company,

> I can't parse this, sorry. What is an "IP company"?

They sell designs for blocks that can be used to build hardware rather
than physical objects or complete chips and they are independant of chip
vendors.  There are a number of other companies that do this, people
like Designware for example, and while ARM do obviously do architectures
they are also a generic soft IP company as well.  This means that for
those companies (and sometimes others) you can't assume that just
because it's used on some architecture that doesn't mean it's used on
others.

> > > might be worth having a FPGA
> > > Kconfig that architectures commonly deployed with lots of soft IPs can
> > > select and the IPs depend on rather than building a custom list for each
> > > IP.

> What are "soft IPs"? I'm afraid I wouldn't be able to translate your
> proposal into a patch, I just don't understand what you mean exactly.

Components used in the design of hardware sold by the above companies.
Several architectures (at least ARM, Microblaze and PowerPC) are
available in chips where most of the chip is a FPGA.

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