Date: Tue, 27 Jun 2017 10:37:11 -0700
From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>,
        Daniel Wagner <wagi@monom.org>, David Woodhouse <dwmw2@infradead.org>,
        rafal@milecki.pl, Arend van Spriel <arend.vanspriel@broadcom.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>, yi1.li@linux.intel.com,
        atull@opensource.altera.com, Moritz Fischer <moritz.fischer@ettus.com>,
        pmladek@suse.com, Johannes Berg <johannes.berg@intel.com>,
        emmanuel.grumbach@intel.com, luciano.coelho@intel.com,
        Kalle Valo <kvalo@codeaurora.org>, luto@kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        "AKASHI, Takahiro" <takahiro.akashi@linaro.org>,
        David Howells <dhowells@redhat.com>, pjones@redhat.com,
        Hans de Goede <hdegoede@redhat.com>, alan@linux.intel.com,
        tytso@mit.edu, lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] firmware: remove request_firmware_into_buf()
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On Mon 26 Jun 23:52 PDT 2017, Greg Kroah-Hartman wrote:

> On Mon, Jun 26, 2017 at 01:22:41PM -0700, Bjorn Andersson wrote:
> > On Fri, Jun 23, 2017 at 9:03 AM, Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > > As Luis pointed out, there are no in-kernel users of
> > > request_firmware_into_buf(), so remove it, and the now unused internal
> > > flag, which simplifies the logic around buffer handling a bit.
> > >
> > 
> > This API was implemented to reduce the memory pressure during firmware
> > load in the Qualcomm remoteprocs, but it wasn't available when I
> > upstreamed that code and I apparently forgot to send out the patch
> > moving us over to use this API...
> > 
> > Especially when loading the Qualcomm modem we have a couple of files
> > that we request_firmware() that are 10-15MB in size, so this
> > functionality is definitely wanted.
> > 
> > 
> > As we are calling release_firmware() immediately following the
> > request_firmware() I did attempt to just call
> > kernel_read_file_from_path() directly, but as I don't have access to
> > the fw_path[] this becomes inconsistent, so I would like to keep
> > request_firmware_into_buf().
> 
> Why would we keep it if there is no in-tree user for it?  If you want it
> sometime in the future, great, we can revert the deletion then, but
> keeping it around for nothing isn't ok, you know that :)
> 

Of course I know that :)

I did put a patch in the tubes for this yesterday [1], it's late for
v4.13, but I would be happy to see the API stay and we would have a user
in v4.14 (and tick this off Qualcomm's "required" list).

[1] https://lkml.org/lkml/2017/6/26/693

Regards,
Bjorn