[PATCH] mmc: card: modify mmc_getgeo function

[Russell King - ARM Linux]

On Mon, Sep 26, 2011 at 03:13:33PM +0200, Uwe Kleine-König wrote:
> 00000028 <mmc_blk_getgeo>:
>       28:       e3a03004        mov     r3, #4
>       2c:       e3a02010        mov     r2, #16
>       30:       e92d4010        push    {r4, lr}
>       34:       e1a04001        mov     r4, r1
>       38:       e5c13000        strb    r3, [r1]
>       3c:       e5c12001        strb    r2, [r1, #1]
>       40:       e590c050        ldr     ip, [r0, #80]   ; 0x50
>       44:       e3a02040        mov     r2, #64 ; 0x40
>       48:       e3a03000        mov     r3, #0
>       4c:       e1cc04d8        ldrd    r0, [ip, #72]   ; 0x48
>       50:       ebfffffe        bl      0 <__aeabi_uldivmod>
>       54:       e1c400b2        strh    r0, [r4, #2]

Yes, this is just silly.  A 64-bit by 64-bit division by a power-of-2
value to ultimately store a 16-bit value.

Even truncating the output from get_capacity() would be better and no
less (in)correct (it may look weird but what the assembly shows is that
it really doesn't matter).  u64 / 64 will give the same 16-bit result as
u64-truncated-to-u32 / 64.