Re: firmware loading interface

[Robert Hancock <hancockrwd@gmail.com>]

On Sat, Nov 14, 2009 at 10:55 AM, venu <vjosyula@gmail.com> wrote:
>  who triggers this upgrade from userspace ? I understand it is a naivee /
> beginers questions but i hope somebody explains me how ?

The request_firmware interface probably isn't suitable for that..
using an ioctl or read/write-based interface, possibly on a separate
device node, would likely be the way to go..

>
> On Sat, Nov 14, 2009 at 9:38 PM, Robert Hancoctk <hancockrwd@gmail.cr tom>
> wrote:
>>
>> On 11/13/2009 06:35 PM, Roland Dreier wrote:
>>>
>>>  >  However our device will have flash to store the firmware in and,
>>> whilst
>>>  >  it looks as though it would be possible for us to use
>>> request_firmware
>>>  >  to provide occasional firmware upgrades from userspace, I can't find
>>> any
>>>  >  reference as to whether this is an accepted method for doing so.
>>> Could
>>>  >  someone please confirm for me whether or not it's a good idea to use
>>>  >  request_firmware for this, or perhaps point me at another standard
>>>  >  method for doing firmware updates from userspace?
>>>
>>> I think request_firmware() is fine for this... you could have a look at
>>> drivers/net/cxgb3 to see a device that writes new firmware to flash when
>>> it detects a version mismatch between driver and device.
>>
>> It depends on the consequences of a failed flash due to losing power,
>> crash, etc - if it has the potential to brick the device then I don't think
>> that should happen without the user triggering it explicitly..