Re: [RFC PATCH 0/5] Extend FW framework for user FW uploads

[Russ Weight <russell.h.weight@intel.com>]

On 2/3/22 3:00 PM, Luis Chamberlain wrote:
> On Thu, Feb 03, 2022 at 02:30:47PM -0700, Russ Weight wrote:
>> Extend the firmware loader subsystem to support a persistent sysfs
>> interface that userspace may use to initiate a firmware update. For
>> example, FPGA based PCIe cards automatically load firmware and FPGA images
>> from local FLASH when the card boots. The images in FLASH may be updated
>> with new images that are uploaded by the user.
>>
>> A device driver may call fw_upload_register() to expose persistent
>> "loading" and "data" sysfs files at /sys/class/firmare/<NAME>/*. These
>> files are used in the same way as the fallback sysfs "loading" and "data"
>> files. However, when 0 is written to "loading" to complete the write of
>> firmware data, the data is also transferred to the lower-level driver
>> using pre-registered call-back functions. The data transfer is done in
>> the context of a kernel worker thread.
>>
>> Additional sysfs nodes are added in the same location as "loading" and
>> "data" to monitor the transfer of the image data to the device using
>> callback functions provided by the lower-level device driver and to allow
>> the data transfer to be cancelled.
>>
>> Example usage:
>>
>> $ pwd
>> /sys/class/firmware/n3000bmc-sec-update.8
>> $ ls
>> cancel  device  loading  remaining_size  subsystem
>> data    error   power    status          uevent
>> $ echo 1 > loading
>> $ cat /tmp/firmware.bin > data
>> $ echo 0 > loading
>> $ while :; do cat status; cat remaining_size ; sleep 3; done
>> preparing
>> 44590080
>> <--snip-->
>> transferring
>> 44459008
>> transferring
>> 44311552
>> <--snip-->
>> <snip>
>> transferring
>> 173056
>> <--snip-->
>> programming
>> 0
>> <--snip-->
>> idle
>> 0
>> ^C
> Nice. Please extend lib/test_firmware.c while at it and try to break
> and ensure your stuff is not regressed with future changes.
Yes. I'm looking at the test_firmware module and I'll add to it
for the next patch submission.

Thanks,
- Russ
>
>   Luis