[lkml]   [2021]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC PATCH 1/5] firmware: Create firmware upload framework
On Wed, Nov 17, 2021 at 10:47:38AM -0800, Russ Weight wrote:
> On 11/17/21 10:18 AM, Greg KH wrote:
> > On Wed, Nov 17, 2021 at 10:00:54AM -0800, Russ Weight wrote:
> >>
> >> On 11/17/21 7:15 AM, Greg KH wrote:
> >>> On Wed, Nov 10, 2021 at 05:13:41PM -0800, Russ Weight wrote:
> >>>> The Firmware Upload class driver provides a common API for uploading
> >>>> firmware files to devices.
> >>> That is exactly what the existing firmware api in the kernel is supposed
> >>> to be accomplishing.
> >>>
> >>> If it is not doing what you need it to do, then you need to document the
> >>> heck out of why it is not, and why you need a different api for this. I
> >>> do not see that here in this changelog at all :(
> >> This is part of the documentation included later in this patch. I can add
> >> this to the changelog.
> >>
> >> +Some devices load firmware from on-board FLASH when the card initializes.
> >> +These cards do not require the request_firmware framework to load the
> >> +firmware when the card boots, but they to require a utility to allow
> >> +users to update the FLASH contents.
> > There's no requirement that request_firmware only be done at boot time,
> > why not use it at any point in time?
> Calling request_firmware() is not restricted to boot time. But it requires
> a firmware filename under /lib/firmware

Not really, there are many locations it can be in. See the different
configuration options we have.

But why would you want firmware in another location?

>, and the convention is to specify the
> filename in the kernel config.

That is not a requirement at all.

> I don't see any support for a user to provide a filename at run time
> to be uploaded to a device, and that is the use case that I want to
> support.

If that's the only difference here, please work with the existing
framework to add that tiny thing (i.e. pass in a name) to the current
framework. Do not create a whole new one please.

> >> When you say "existing firmware api", I'm thinking request_firmware, which
> >> requires that driver names be specified in the kernel config and wants to
> >> load firmware automatically during device initialization.
> > It can be used at any time, why do you think it's restricted to init
> > time?
> >
> > And I do not understand your issue with driver names.
> Sorry - I meant so say "firmware file names"
> In an earlier iteration of this patchset, you pointed out that allowing a user
> to provide a filename for request_firmware() to use was a security issue.

It is crazy, don't you think?

> The use case that I am targeting is to allow a user to provide an image file
> to a device at run time.

That's not a limitation of the existing firmware layer.


greg k-h

 \ /
  Last update: 2021-11-17 19:54    [W:0.058 / U:2.560 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site