Why does lpfc select GENERIC_CSUM?

Why does lpfc select GENERIC_CSUM?

[Anton Blanchard]

Hi Randy,

commit 6a7252fd ([SCSI] lpfc: fix up Kconfig dependencies) added a
select of GENERIC_CSUM. This seems strange to me - it's an architecture
specific detail if the checksum routines are implemented in assembly or
if they pull in lib/checksum.c.

The networking code doesn't select GENERIC_CSUM, so I'm not sure why
the lpfc driver needs to. Was there a real issue we hit here?

Regards,
Anton

Re: Why does lpfc select GENERIC_CSUM?

[Randy Dunlap]

On 08/05/13 03:20, Anton Blanchard wrote:
> 
> Hi Randy,
> 
> commit 6a7252fd ([SCSI] lpfc: fix up Kconfig dependencies) added a
> select of GENERIC_CSUM. This seems strange to me - it's an architecture
> specific detail if the checksum routines are implemented in assembly or
> if they pull in lib/checksum.c.
> 
> The networking code doesn't select GENERIC_CSUM, so I'm not sure why
> the lpfc driver needs to. Was there a real issue we hit here?
> 
> Regards,
> Anton
> 

Hi Anton,

I reported:
"""
on i386:
# CONFIG_CRC_T10DIF is not set


drivers/built-in.o: In function `lpfc_bg_crc':
(.text+0x3cb3c9): undefined reference to `crc_t10dif'
"""

and then James Bottomley provided the patch.
I don't know why he added GENERIC_CSUM to it.

-- 
~Randy

[SCSI] lpfc: Don't force CONFIG_GENERIC_CSUM on

[Anton Blanchard]

Hi Randy,

> I reported:
> """
> on i386:
> # CONFIG_CRC_T10DIF is not set
> 
> 
> drivers/built-in.o: In function `lpfc_bg_crc':
> (.text+0x3cb3c9): undefined reference to `crc_t10dif'
> """
> 
> and then James Bottomley provided the patch.
> I don't know why he added GENERIC_CSUM to it.

Thanks for investigating this. How does this patch look?

Anton
--

[SCSI] lpfc: Don't force CONFIG_GENERIC_CSUM on

We want ppc64 to be able to select between optimised assembly
checksum routines in big endian and the generic lib/checksum.c
routines in little endian.

The lpfc driver is forcing CONFIG_GENERIC_CSUM on which means
we are unable to make the decision to enable it in the arch
Kconfig. If the option exists it is always forced on.

This got introduced in 3.10 via commit 6a7252fdb0c3 ([SCSI] lpfc:
fix up Kconfig dependencies). I spoke to Randy about it and
the original issue was with CRC_T10DIF not being defined.

As such, remove the select of CONFIG_GENERIC_CSUM.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@vger.kernel.org> # 3.10
---

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 48b2918..92ff027 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -1353,7 +1353,6 @@ config SCSI_LPFC
 	tristate "Emulex LightPulse Fibre Channel Support"
 	depends on PCI && SCSI
 	select SCSI_FC_ATTRS
-	select GENERIC_CSUM
 	select CRC_T10DIF
 	help
           This lpfc driver supports the Emulex LightPulse

Re: [SCSI] lpfc: Don't force CONFIG_GENERIC_CSUM on

[James Smart]

I'm good with it. You folks understand the config dependencies better 
than I.

-- james

Acked-By:  James Smart  <james.smart@emulex.com>


On 8/8/2013 3:47 AM, Anton Blanchard wrote:
> Hi Randy,
>
>> I reported:
>> """
>> on i386:
>> # CONFIG_CRC_T10DIF is not set
>>
>>
>> drivers/built-in.o: In function `lpfc_bg_crc':
>> (.text+0x3cb3c9): undefined reference to `crc_t10dif'
>> """
>>
>> and then James Bottomley provided the patch.
>> I don't know why he added GENERIC_CSUM to it.
> Thanks for investigating this. How does this patch look?
>
> Anton
> --
>
> [SCSI] lpfc: Don't force CONFIG_GENERIC_CSUM on
>
> We want ppc64 to be able to select between optimised assembly
> checksum routines in big endian and the generic lib/checksum.c
> routines in little endian.
>
> The lpfc driver is forcing CONFIG_GENERIC_CSUM on which means
> we are unable to make the decision to enable it in the arch
> Kconfig. If the option exists it is always forced on.
>
> This got introduced in 3.10 via commit 6a7252fdb0c3 ([SCSI] lpfc:
> fix up Kconfig dependencies). I spoke to Randy about it and
> the original issue was with CRC_T10DIF not being defined.
>
> As such, remove the select of CONFIG_GENERIC_CSUM.
>
> Signed-off-by: Anton Blanchard <anton@samba.org>
> Cc: <stable@vger.kernel.org> # 3.10
> ---
>
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index 48b2918..92ff027 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -1353,7 +1353,6 @@ config SCSI_LPFC
>   	tristate "Emulex LightPulse Fibre Channel Support"
>   	depends on PCI && SCSI
>   	select SCSI_FC_ATTRS
> -	select GENERIC_CSUM
>   	select CRC_T10DIF
>   	help
>             This lpfc driver supports the Emulex LightPulse
>