[PATCH] Firmware: broadcom sprom: clarifiy SSB dependency

[PATCH] Firmware: broadcom sprom: clarifiy SSB dependency

[Arnd Bergmann]

The broadcom firmware drvier calls into the ssb SPROM code if that
is enabled, but it fails if the SSB code is in a loadable module
because the bcm47xx firmware is always built-in:

drivers/firmware/built-in.o: In function `bcm47xx_sprom_register_fallbacks':
bcm47xx_sprom.c:(.text+0x11c4): undefined reference to `ssb_arch_register_fallback_sprom'

This adds a Kconfig dependency to ensure that we cannot turn on the
generic sprom support if the ssb sprom is in a module.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/firmware/broadcom/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/firmware/broadcom/Kconfig b/drivers/firmware/broadcom/Kconfig
index 3c7e5b741e37..42f7d9bfb148 100644
--- a/drivers/firmware/broadcom/Kconfig
+++ b/drivers/firmware/broadcom/Kconfig
@@ -13,6 +13,7 @@ config BCM47XX_NVRAM
 config BCM47XX_SPROM
 	bool "Broadcom SPROM driver"
 	depends on BCM47XX_NVRAM
+	depends on SSB=y || SSB=n
 	help
 	  Broadcom devices store configuration data in SPROM. Accessing it is
 	  specific to the bus host type, e.g. PCI(e) devices have it mapped in
-- 
2.7.0

Re: [PATCH] Firmware: broadcom sprom: clarifiy SSB dependency

[Rafał Miłecki]

On 14 March 2016 at 15:21, Arnd Bergmann <arnd@arndb.de> wrote:
> The broadcom firmware drvier calls into the ssb SPROM code if that
> is enabled, but it fails if the SSB code is in a loadable module
> because the bcm47xx firmware is always built-in:
>
> drivers/firmware/built-in.o: In function `bcm47xx_sprom_register_fallbacks':
> bcm47xx_sprom.c:(.text+0x11c4): undefined reference to `ssb_arch_register_fallback_sprom'
>
> This adds a Kconfig dependency to ensure that we cannot turn on the
> generic sprom support if the ssb sprom is in a module.

Can you attach your config that triggered this build error? I modified
condition to the:
#if IS_BUILTIN(CONFIG_SSB) && IS_ENABLED(CONFIG_SSB_SPROM)
which I believe should be enough.

I'm afraid your patch won't allow compiling SPROM driver with BCMA=y
and SSB as a module.

Re: [PATCH] Firmware: broadcom sprom: clarifiy SSB dependency

[Arnd Bergmann]

On Monday 14 March 2016 15:37:18 Rafał Miłecki wrote:
> On 14 March 2016 at 15:21, Arnd Bergmann <arnd@arndb.de> wrote:
> > The broadcom firmware drvier calls into the ssb SPROM code if that
> > is enabled, but it fails if the SSB code is in a loadable module
> > because the bcm47xx firmware is always built-in:
> >
> > drivers/firmware/built-in.o: In function `bcm47xx_sprom_register_fallbacks':
> > bcm47xx_sprom.c:(.text+0x11c4): undefined reference to `ssb_arch_register_fallback_sprom'
> >
> > This adds a Kconfig dependency to ensure that we cannot turn on the
> > generic sprom support if the ssb sprom is in a module.
> 
> Can you attach your config that triggered this build error? I modified
> condition to the:
> #if IS_BUILTIN(CONFIG_SSB) && IS_ENABLED(CONFIG_SSB_SPROM)
> which I believe should be enough.

>From inspection, I think your solution is sufficient to avoid the error.
I found the bug while travelling and I'm only now catching up on the submissions,
so I must have missed the fact that it was fixed. I looked at the code
to see if additional patches had been applied on top, but I did not
realize that you had modified the driver in place.

> I'm afraid your patch won't allow compiling SPROM driver with BCMA=y
> and SSB as a module.

Correct. The downside of your approach is that it silently stops the machine
from accessing the SSB SPROM when the driver is a module, while still
allowing the generic SPROM code to be built, which may be harder to
figure out for a user than a missing driver.

I don't see a good solution that works either way, so the your latest code looks
good enough. Thanks for the quick reply!

	Arnd

Re: [PATCH] Firmware: broadcom sprom: clarifiy SSB dependency

[Rafał Miłecki]

On 14 March 2016 at 16:34, Arnd Bergmann <arnd@arndb.de> wrote:
> On Monday 14 March 2016 15:37:18 Rafał Miłecki wrote:
>> On 14 March 2016 at 15:21, Arnd Bergmann <arnd@arndb.de> wrote:
>> > The broadcom firmware drvier calls into the ssb SPROM code if that
>> > is enabled, but it fails if the SSB code is in a loadable module
>> > because the bcm47xx firmware is always built-in:
>> >
>> > drivers/firmware/built-in.o: In function `bcm47xx_sprom_register_fallbacks':
>> > bcm47xx_sprom.c:(.text+0x11c4): undefined reference to `ssb_arch_register_fallback_sprom'
>> >
>> > This adds a Kconfig dependency to ensure that we cannot turn on the
>> > generic sprom support if the ssb sprom is in a module.
>>
>> Can you attach your config that triggered this build error? I modified
>> condition to the:
>> #if IS_BUILTIN(CONFIG_SSB) && IS_ENABLED(CONFIG_SSB_SPROM)
>> which I believe should be enough.
>
> From inspection, I think your solution is sufficient to avoid the error.
> I found the bug while travelling and I'm only now catching up on the submissions,
> so I must have missed the fact that it was fixed. I looked at the code
> to see if additional patches had been applied on top, but I did not
> realize that you had modified the driver in place.

I sent a separated patch for this:
https://patchwork.linux-mips.org/patch/12836/
and it was folded/squashed by Ralf.

-- 
Rafał