Re: [PATCH v4 1/6] mtd: nand: vf610_nfc: Freescale NFC for VF610, MPC5125 and others

Stefan Agner
2015-06-09T20:33:33Z

On 2015-06-09 22:07, Sebastian Andrzej Siewior wrote:
> On 2015-06-03 17:05:16 [+0200], Stefan Agner wrote:
>> As Boris guessed correctly, the reason I used the raw variant was due to
>> performance improvements due to the barrier. However, I will use
>
> yeah, do you have any numbers by chance?

Not current ones for Linux. I added this in the U-Boot variant of the
driver.

>> {read|write}l_relaxed instead, which should offer endian abstraction
>> while not having the performance penalty due to extensive barriers...
>
> well, even those
> |$ git grep readl_relaxed arch/powerpc/
> |arch/powerpc/include/asm/io.h:#define readl_relaxed(addr) readl(addr)
>
> have the endian swap. So an abstraction like you provided earlier
> would be nice :)

What do you mean by that?

Btw, I sent v5 of the patchset which use the relaxed variants. As
expected, performance did not suffer by that change on ARM.

--
Stefan