[-mm PATCH] DMA engine kconfig improvements (rev2)

[-mm PATCH] DMA engine kconfig improvements (rev2)

[Shannon Nelson]

From: Adrian Bunk <bunk@stusta.de>

This patch contains the following changes to the DMA engine menus:
- switch to menuconfig
- INTEL_IOATDMA must depend on X86
- INTEL_IOATDMA must select DCA
- device drivers shouldn't "default m"
- DCA shouldn't be a user visible option
- make it clear in the INTEL_IOATDMA help text that this driver is for
  rare hardware the user most likely doesn't has
- let DMA_ENGINE be select'ed by the DMA devices, making it less likely
  for a user to accidentally enable NET_DMA

[dan.j.williams@intel.com: fix up Kconfig text]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
---

 drivers/dca/Kconfig |    7 ++----
 drivers/dma/Kconfig |   60 ++++++++++++++++++++++++++++++---------------------
 2 files changed, 37 insertions(+), 30 deletions(-)

diff --git a/drivers/dca/Kconfig b/drivers/dca/Kconfig
index d901615..c2ed77c 100644
--- a/drivers/dca/Kconfig
+++ b/drivers/dca/Kconfig
@@ -3,9 +3,6 @@
 #
 
 config DCA
-	tristate "DCA support for clients and providers"
-	---help---
-          This is a server to help modules that want to use Direct Cache
-	  Access to find DCA providers that will supply correct CPU tags.
-	default m
+	tristate
+
 
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 8f670da..955a99b 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -2,42 +2,52 @@
 # DMA engine configuration
 #
 
-menu "DMA Engine support"
-	depends on HAS_DMA
+menuconfig DMADEVICES
+	bool "DMA Offload Engine support"
+	depends on (PCI && X86) || ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX
+	help
+	  Intel(R) offload engines enable offloading memory copies in the
+	  network stack and RAID operations in the MD driver.
+
+if DMADEVICES
+
+comment "DMA Devices"
+
+config INTEL_IOATDMA
+	tristate "Intel I/OAT DMA support"
+	depends on PCI && X86
+	select DMA_ENGINE
+	select DCA
+	help
+	  Enable support for the Intel(R) I/OAT DMA engine present
+	  in recent chipsets.
+
+	  Say Y here if you have such a chipset.
+
+	  If unsure, say N.
+
+config INTEL_IOP_ADMA
+	tristate "Intel IOP ADMA support"
+	depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX
+	select ASYNC_CORE
+	select DMA_ENGINE
+	help
+	  Enable support for the Intel(R) IOP Series RAID engines.
 
 config DMA_ENGINE
-	bool "Support for DMA engines"
-	---help---
-          DMA engines offload bulk memory operations from the CPU to dedicated
-          hardware, allowing the operations to happen asynchronously.
+	bool
 
 comment "DMA Clients"
+	depends on DMA_ENGINE
 
 config NET_DMA
 	bool "Network: TCP receive copy offload"
 	depends on DMA_ENGINE && NET
 	default y
-	---help---
+	help
 	  This enables the use of DMA engines in the network stack to
 	  offload receive copy-to-user operations, freeing CPU cycles.
 	  Since this is the main user of the DMA engine, it should be enabled;
 	  say Y here.
 
-comment "DMA Devices"
-
-config INTEL_IOATDMA
-	tristate "Intel I/OAT DMA support"
-	depends on DMA_ENGINE && PCI
-	default m
-	---help---
-	  Enable support for the Intel(R) I/OAT DMA engine.
-
-config INTEL_IOP_ADMA
-        tristate "Intel IOP ADMA support"
-        depends on DMA_ENGINE && (ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX)
-	select ASYNC_CORE
-        default m
-        ---help---
-          Enable support for the Intel(R) IOP Series RAID engines.
-
-endmenu
+endif

Re: [-mm PATCH] DMA engine kconfig improvements (rev2)

[Adrian Bunk]

On Thu, Aug 16, 2007 at 05:10:25PM -0700, Shannon Nelson wrote:
> From: Adrian Bunk <bunk@stusta.de>
> 
> This patch contains the following changes to the DMA engine menus:
>...
> - make it clear in the INTEL_IOATDMA help text that this driver is for
>   rare hardware the user most likely doesn't has
>...
> +config INTEL_IOATDMA
> +	tristate "Intel I/OAT DMA support"
> +	depends on PCI && X86
> +	select DMA_ENGINE
> +	select DCA
> +	help
> +	  Enable support for the Intel(R) I/OAT DMA engine present
> +	  in recent chipsets.
>...

It seems the string "Xeon" somehow got lost, or is it now also 
available with other hardware?

"in recent Intel Xeon chipsets"?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

RE: [-mm PATCH] DMA engine kconfig improvements (rev2)

[Nelson, Shannon]

>From: Adrian Bunk [mailto:bunk@kernel.org] 
>Sent: Thursday, August 16, 2007 5:48 PM
>To: Nelson, Shannon
>Cc: akpm@linux-foundation.org; linux-kernel@vger.kernel.org; 
>Williams, Dan J; ssatyam@cse.iitk.ac.in
>Subject: Re: [-mm PATCH] DMA engine kconfig improvements (rev2)
>
>On Thu, Aug 16, 2007 at 05:10:25PM -0700, Shannon Nelson wrote:
>> From: Adrian Bunk <bunk@stusta.de>
>> 
>> This patch contains the following changes to the DMA engine menus:
>>...
>> - make it clear in the INTEL_IOATDMA help text that this 
>driver is for
>>   rare hardware the user most likely doesn't has
>>...
>> +config INTEL_IOATDMA
>> +	tristate "Intel I/OAT DMA support"
>> +	depends on PCI && X86
>> +	select DMA_ENGINE
>> +	select DCA
>> +	help
>> +	  Enable support for the Intel(R) I/OAT DMA engine present
>> +	  in recent chipsets.
>>...
>
>It seems the string "Xeon" somehow got lost, or is it now also 
>available with other hardware?
>
>"in recent Intel Xeon chipsets"?
>
>cu
>Adrian

Good catch - however, it is probably best not to limit these things.

sln
--
======================================================================
Mr. Shannon Nelson                 LAN Access Division, Intel Corp.
Shannon.Nelson@intel.com                I don't speak for Intel
(503) 712-7659                    Parents can't afford to be squeamish.

Re: [-mm PATCH] DMA engine kconfig improvements (rev2)

[Adrian Bunk]

On Fri, Aug 17, 2007 at 08:59:29AM -0700, Nelson, Shannon wrote:
> >From: Adrian Bunk [mailto:bunk@kernel.org] 
> >Sent: Thursday, August 16, 2007 5:48 PM
> >To: Nelson, Shannon
> >Cc: akpm@linux-foundation.org; linux-kernel@vger.kernel.org; 
> >Williams, Dan J; ssatyam@cse.iitk.ac.in
> >Subject: Re: [-mm PATCH] DMA engine kconfig improvements (rev2)
> >
> >On Thu, Aug 16, 2007 at 05:10:25PM -0700, Shannon Nelson wrote:
> >> From: Adrian Bunk <bunk@stusta.de>
> >> 
> >> This patch contains the following changes to the DMA engine menus:
> >>...
> >> - make it clear in the INTEL_IOATDMA help text that this 
> >driver is for
> >>   rare hardware the user most likely doesn't has
> >>...
> >> +config INTEL_IOATDMA
> >> +	tristate "Intel I/OAT DMA support"
> >> +	depends on PCI && X86
> >> +	select DMA_ENGINE
> >> +	select DCA
> >> +	help
> >> +	  Enable support for the Intel(R) I/OAT DMA engine present
> >> +	  in recent chipsets.
> >>...
> >
> >It seems the string "Xeon" somehow got lost, or is it now also 
> >available with other hardware?
> >
> >"in recent Intel Xeon chipsets"?
> >
> >cu
> >Adrian
> 
> Good catch - however, it is probably best not to limit these things.

Since the effects of CONFIG_NET_DMA are considered big enough to warrant 
all these #ifdef's in the net code it should be made clear for the user 
that this is only for hardware he most likely doesn't has.

And it's not about any kind of kconfig dependency, it's simply about the 
help text.

> sln

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed