Re: [PATCH v4 2/2] efi: an sysfs interface for user to update efi firmware

[Greg Kroah-Hartman <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>]

On Tue, Apr 14, 2015 at 11:52:48AM -0400, Andy Lutomirski wrote:
> On Tue, Apr 14, 2015 at 10:09 AM, Greg Kroah-Hartman
> <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org> wrote:
> > On Tue, Apr 14, 2015 at 05:44:56PM +0800, Kweh, Hock Leong wrote:
> >> From: "Kweh, Hock Leong" <hock.leong.kweh-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >>
> >> Introducing a kernel module to expose capsule loader interface
> >> for user to upload capsule binaries. This module leverage the
> >> request_firmware_direct_full_path() to obtain the binary at a
> >> specific path input by user.
> >>
> >> Example method to load the capsule binary:
> >> echo -n "/path/to/capsule/binary" > /sys/devices/platform/efi_capsule_loader/capsule_loader
> >
> > Ick, why not just have the firmware file location present, and copy it
> > to the sysfs file directly from userspace, instead of this two-step
> > process?
> 
> Because it's not at all obvious how error handling should work in that case.

I don't understand how the error handling is any different.  The kernel
ends up copying the data in through the firmware interface both ways, we
just aren't creating yet-another-firmware-path in the system.

thanks,

greg k-h