RE: [PATCH] mmc-utils: Add softreset command for issuing CMD0

[Christian Loehle <CLoehle@hyperstone.com>]

>> CMD0 may be used to see if the hardware can handle a UHS card
>> that completed the voltage switch. If a UHS card has problems
>> coming back up after CMD0 your hardware may not support a hard
>> reset properly.
>I think it's a useful addition, not just for that reason.
>Specifically to test hw-reset support, I think you should use the GO_PRE_IDLE_STATE option.

Makes sense to add both, I can do that.

>
>> +
>> +       memset(&idata, 0, sizeof(idata));
>> +       idata.opcode = MMC_GO_IDLE_STATE;
>> +       idata.flags = MMC_RSP_NONE | MMC_CMD_BC;
>How about adding all 3 flavors of soft-reset: GO_IDLE_STATE, GO_PRE_IDLE_STATE, and BOOT_INITIATION.
>There can be 3 different command, that calls the same __soft_reset helper, or whatever.
>What do you think?  

I'm fine with GO_IDLE_STATE and GO_PRE_IDLE_STATE, but BOOT_INITATION Im not sure about, what purpose would it serve?
If the intention is to be able to get the boot operation done with multi_cmd of GO_PRE_IDLE_STATE and BOOT_INITATION and return the data then that would at least be some more testing effort before I resend.
I have only done the boot operations completely in the driver so far.
Furthermore I think many (most?) host controllers (or our drivers) seem to have issues with the transfer size I'd expect of a normal boot operation (i.e 4-32MB).

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