Re: [PATCH v2] scsi: sd: add new match array for cache_type

["Martin K. Petersen" <martin.petersen@oracle.com>]

Hi Weiping,

> currently, there are four combinations as following: "write through",
> "none", "write back", "write back, no read (daft)"
>
> cache_type can control both write and read cache, but for "write
> through" and "write back" we can not know clearly how to control the
> read cache.

That's what I meant by using the term "arcane" and alluding to the fact
that this interface is not well enough documented.

> I prefer use words like"w0r1", "w0r0", "w1r1", "w1r0", that "1" means
> enable, "0" means disable. The user know clearly what they are doing
> when typing these short words.

We can't change the existing interface without breaking stuff. We can
entertain adding stuff, but I do think that a better solution is to
document what's there so the effect of echoing each of the following
strings becomes crystal clear:

static const char *sd_cache_types[] = {
        "write through", "none", "write back",
        "write back, no read (daft)"
};

I would also like to see the "temporary" string documented.

-- 
Martin K. Petersen	Oracle Linux Engineering