Re: [PATCH RESEND v3 3/7] Intel MIC Host Driver, card OS state management.

[Sudeep Dutt <sudeep.dutt@intel.com>]

On Fri, 2013-09-06 at 12:04 -0700, Greg Kroah-Hartman wrote:
> On Fri, Sep 06, 2013 at 11:41:03AM -0700, Sudeep Dutt wrote:
> > On Thu, 2013-09-05 at 22:01 -0700, Greg Kroah-Hartman wrote:
> > > On Thu, Sep 05, 2013 at 04:41:55PM -0700, Sudeep Dutt wrote:
> > > > +What:		/sys/class/mic/mic(x)/firmware
> > > > +Date:		August 2013
> > > > +KernelVersion:	3.11
> > > > +Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
> > > > +Description:
> > > > +		When read, this sysfs entry provides the path name under
> > > > +		/lib/firmware/ where the firmware image to be booted on the
> > > > +		card can be found. The entry can be written to change the
> > > > +		firmware image location under /lib/firmware/.
> > > 
> > > I don't understand, is the path under the HOST device, or the Client
> > > device's disk?  Why do you need to change the path on the HOST?  What's
> > > wrong with the existing firmware path selection we have in the kernel?
> > > 
> > 
> > The path is on the host. The card does not have a physical persistent
> > disk device. Our customers like the flexibility of changing the card
> > firmware/ramdisk contents and file names for individual MIC cards. This
> > flexibility is not possible with a static set of firmware file names in
> > the kernel for all cards.
> > 
> > Once the firmware/ramdisk path under /lib/firmware/ is set up via sysfs,
> > card boot is initiated via the "state" sysfs entry. The host driver then
> > obtains the contents of the firmware and ramdisk via the standard
> > request_firmware(..) interface, copies the contents to card memory and
> > interrupts the card BIOS to initiate boot.
> 
> So this is really a "filename" that might contain some directories as
> well, right?  The fact you used "path" confused me, as that doesn't
> usually imply a filename.
> 

Yes, it is a filename that might contain some directories. We will fix
up the documentation here to read filename in future patches.

> And is the "firmware" just the initramfs image for the kernel to boot?
> 

The firmware is usually a Linux kernel. The ramdisk is usually an
initramfs image. We have separate sysfs entries for firmware and ramdisk
filenames.

Thanks,
Sudeep Dutt

> thanks,
> 
> greg k-h