[PATCH v3] powerpc/fsl-85xx: fix compile error

[Michael Ellerman]

王文虎 <wenhu.wang at vivo.com> writes:
> From: Michael Ellerman <mpe at ellerman.id.au>
>  Date: 2020-03-16 17:41:12
> To:WANG Wenhu <wenhu.wang at vivo.com>,Benjamin Herrenschmidt <benh at kernel.crashing.org>,Paul Mackerras <paulus at samba.org>,WANG Wenhu <wenhu.wang at vivo.com>,Allison Randal <allison at lohutok.net>,Richard Fontana <rfontana at redhat.com>,Greg Kroah-Hartman <gregkh at linuxfoundation.org>,Thomas Gleixner <tglx at linutronix.de>,linuxppc-dev at lists.ozlabs.org,linux-kernel at vger.kernel.org
>  cc: trivial at kernel.org,kernel at vivo.com,stable <stable at vger.kernel.org>
> Subject: Re: [PATCH v3] powerpc/fsl-85xx: fix compile error>WANG Wenhu <wenhu.wang at vivo.com> writes:
>>> Include "linux/of_address.h" to fix the compile error for
>>> mpc85xx_l2ctlr_of_probe() when compiling fsl_85xx_cache_sram.c.
>>>
>>>   CC      arch/powerpc/sysdev/fsl_85xx_l2ctlr.o
>>> arch/powerpc/sysdev/fsl_85xx_l2ctlr.c: In function ‘mpc85xx_l2ctlr_of_probe’:
>>> arch/powerpc/sysdev/fsl_85xx_l2ctlr.c:90:11: error: implicit declaration of function ‘of_iomap’; did you mean ‘pci_iomap’? [-Werror=implicit-function-declaration]
>>>   l2ctlr = of_iomap(dev->dev.of_node, 0);
>>>            ^~~~~~~~
>>>            pci_iomap
>>> arch/powerpc/sysdev/fsl_85xx_l2ctlr.c:90:9: error: assignment makes pointer from integer without a cast [-Werror=int-conversion]
>>>   l2ctlr = of_iomap(dev->dev.of_node, 0);
>>>          ^
>>> cc1: all warnings being treated as errors
>>> scripts/Makefile.build:267: recipe for target 'arch/powerpc/sysdev/fsl_85xx_l2ctlr.o' failed
>>> make[2]: *** [arch/powerpc/sysdev/fsl_85xx_l2ctlr.o] Error 1
>>>
>>> Fixes: commit 6db92cc9d07d ("powerpc/85xx: add cache-sram support")
>>
>>The syntax is:
>>
>>Fixes: 6db92cc9d07d ("powerpc/85xx: add cache-sram support")
>>
>>> Cc: stable <stable at vger.kernel.org>
>>
>>The commit above went into v2.6.37.
>>
>>So no one has noticed this bug since then, how? Or did something else
>>change to expose the problem?
>
> Actually a hard question to answer cause it also left me scratching for long.
> However, I can not find right or definite answer.

Oh, actually it's fairly straight forward, the code can't be built at
all in upstream because CONFIG_FSL_85XX_CACHE_SRAM is not selectable or
selected by anything.

You sent a patch previously to make it selectable, which Scott thought
was a bad idea.

So this whole file is dead code as far as I'm concerned, so patches for
it definitely do not need to go to stable.

If you want to add a user for it then please send a series doing that,
and this commit can be the first.

cheers