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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Fri, 6 Apr 2018 09:22:18 +0200
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Subject: Re: [4.9, 137/145] spi: bcm-qspi: shut up warning about cfi header inclusion
To:     "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "# 3.4.x" <stable@vger.kernel.org>,
        Kamal Dasu <kdasu.kdev@gmail.com>
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On Fri, Apr 6, 2018 at 9:09 AM, gregkh@linuxfoundation.org
<gregkh@linuxfoundation.org> wrote:
> On Tue, Apr 03, 2018 at 10:46:07AM -0700, Florian Fainelli wrote:
>> On 02/23/2018 10:27 AM, gregkh@linuxfoundation.org wrote:
>> > 4.9-stable review patch.  If anyone has any objections, please let me know.
>> >
>> > ------------------
>> >
>> > From: Arnd Bergmann <arnd@arndb.de>
>> >
>> > When CONFIG_MTD_CFI is disabled, we get a warning for this spi driver:
>> >
>> > include/linux/mtd/cfi.h:76:2: #warning No CONFIG_MTD_CFI_Ix selected. No NOR chip support can work. [-Werror=cpp]
>> >
>> > The problem here is a layering violation that was fixed in mainline kernels with
>> > a larger rework in commit 054e532f8f90 ("spi: bcm-qspi: Remove hardcoded settings
>> > and spi-nor.h dependency"). We can't really backport that to stable kernels, so
>> > this just adds a Kconfig dependency to make it either build cleanly or force it
>> > to be disabled.
>>
>> Sorry for noticing so late, but this appears to be bogus, there is no
>> MTD_NORFLASH symbol being defined in 4.9, in fact I can't find this
>> Kconfig symbol in any kernel version, so this effectively results in the
>> driver no longer being selectable, so this sure does silence the warning.
>>
>> Arnd, should we just send reverts of this patch for the affected kernel
>> or should we be defining MTD_NORFLASH somehow? Am I missing something here?
>
> I'm going to revert this patch for now, thanks.

Yes, please do. Sorry for missing Florian's bug report. I looked at it again
and found that it was never intended for backports to 4.9, as the regression
addressed by the patch was originally merged into 4.14-rc1.

       Arnd