Re: [RFC] p54: software hot-swap eeprom image

[Dan Williams <dcbw@redhat.com>]

On Fri, 2009-11-20 at 23:02 +0200, Kalle Valo wrote:
> Dan Williams <dcbw@redhat.com> writes:
> 
> >> Wasn't the concensus that request_firmware() will be used for this
> >> kind of device specific data? stlc45xx had a similar sysfs interface
> >> and people didn't like it. And I tend to agree with them, adding odd
> >> sysfs files is not the best way to handle this.
> >
> > It could be yes, but what would the trigger to upload the new firmware
> > be?  A /standard/ sysfs file that you
> >
> > echo "new-firmware-v345" > eeprom_write
> >
> > into that would then request_firmware("new-firmware-v345")?
> 
> To be sure that we are talking about the same stuff, let's clarify
> this a bit first. There are two different use cases where eeprom from
> user space is needed:
> 
> Category 1. Devices which don't have eeprom at all and require the
>             user space provides the eeprom data during every device
>             boot. These devices won't even function correctly if they
>             don't get the correct eeprom data from user space. As an
>             example, grep nvs from wl12xx.

Obviously; pretty much every driver that needs firmware does this
already, yeah.  And uses request_firmware().

> Category 2. Devices which have eeprom but can be updated by user.

I was under the impression that chr's original patch was doing #2 here.
Run-time update of firmware.  I guess if the device doesn't actually
write the new firmware to eeprom then yeah, use #1.  Thought his case
was #2 or something.

Dan