[U-Boot] [PATCH 2/3] common: dfu: ignore reset for spl-dfu

[B, Ravi]

Hi Tom

>> The SPL-DFU feature enable to load and execute u-boot over usb from PC 
>> using dfu-util.
>> Hence dfu-reset should not be issued
>> when dfu-util -R switch is issued.
>> 
>> Signed-off-by: Ravi Babu <ravibabu at ti.com>
>> ---
>>  common/dfu.c | 3 +++
>>  1 file changed, 3 insertions(+)
>> 
>> diff --git a/common/dfu.c b/common/dfu.c index 0e9f5f5..fa77526 100644
>> --- a/common/dfu.c
>> +++ b/common/dfu.c
>> @@ -87,6 +87,9 @@ exit:
>>  	g_dnl_unregister();
>>  	board_usb_cleanup(usbctrl_index, USB_INIT_DEVICE);
>>  
>> +#ifdef CONFIG_SPL_BUILD
>> +	dfu_reset = 0;
>> +#endif
>>  	if (dfu_reset)
>>  		run_command("reset", 0);

>So we "fix" some of the problems we see by saying that you can't reset the board in SPL via DFU. 
> I think maybe we should instead drop run_command here and make reset-via-DFU call do_reset() directly like some other small-size-required cases do.  This will let us drop the command >requirement here but still allow for "use DFU to flash and reset the board with just SPL" as a use-case.  Thanks!

The SPL-DFU will load and execute u-boot.img from RAM.  If we issue dfu-reset (-R switch), this leads to cpu-reset and we lost the purpose of SPL-DFU itself.
Hence dfu-reset issue shall not be issued for SPL-DFU. 

I agree, the dfu-reset is needed in u-boot, after flashing images to QSPI/eMMC/SD using the DFU to execute newly loaded image.
So, dfu-reset is needed for u-boot, but not required for SPL-DFU.

For u-boot, we can continue to use run_command() for dfu-reset.

Regards
Ravi