Re: Re: [PATCH v2 3/3] efi: Capsule update with user helper interface - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Matt Fleming <matt@console-pimps.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
	Peter Jones <pjones@redhat.com>,
	"Kweh, Hock Leong" <hock.leong.kweh@intel.com>,
	Sam Protsenko <semen.protsenko@linaro.org>,
	Ming Lei <ming.lei@canonical.com>,
	"Ong, Boon Leong" <boon.leong.ong@intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>
Subject: Re: Re: [PATCH v2 3/3] efi: Capsule update with user helper interface
Date: Fri, 13 Mar 2015 15:42:13 +0100	[thread overview]
Message-ID: <20150313144213.GA19009@kroah.com> (raw)
In-Reply-To: <20150312224754.GD24174@codeblueprint.co.uk>

On Thu, Mar 12, 2015 at 10:47:54PM +0000, Matt Fleming wrote:
> On Tue, 10 Mar, at 08:51:59AM, Andy Lutomirski wrote:
> > 
> > I'm not 100% happy with write(2) (which is all we have in sysfs) for
> > two reasons:
> > 
> > 1. If we write a file name, eww.  That's more complicated, requires
> > temporary files, has annoying mount namespace issues, etc.
> > 
> > 2. If we write the full contents, we need to do it in a single call to
> > write.  That means that we can't use cat, which mostly defeats the
> > purpose.  In fact, using cat could be actively harmful.
> 
> At this point I'd really like Greg to chime in.
> 
> In principal, I'm not stricly opposed to using a simple char device
> provided that it's not essentially a copy and paste of code from
> drivers/base/firmware_class.c.
> 
> Greg?

Yes, I don't want a character driver here for this if at all possible.
Just stick with the firmware download code, it's there and should work
"as-is" for your stuff.

thanks,

greg k-h