[PATCH v2 3/4] mtd: mxc_nand: fix truncate of unaligned oob copying

[Uwe Kleine-König]

On Wed, May 13, 2015 at 08:12:02AM +0300, Baruch Siach wrote:
> Hi Uwe,
> 
> On Fri, May 08, 2015 at 09:24:32AM +0200, Uwe Kleine-König wrote:
> > On Sun, May 03, 2015 at 10:18:53AM +0300, Baruch Siach wrote:
> > > Copy to/from oob io area might not be aligned to 4 bytes. When 8 bit ECC is
> > > used, the buffer size is 26. Add memcpy16_{to,from}io, and use them to avoid
> > > truncating the buffer. Prefer memcpy32_{to,from}io when the buffer is properly
> > > aligned for better performance.
> > Did you measure this performance difference? I doubt it's worth the
> > complexity given that we're talking about buffers with a size of up to
> > 26 bytes.
> 
> We'll need both memcpy16_{to,from}io and memcpy32_{to,from}io anyway. So by 
> "complexity" you refer to the additional alignment check and memcpy32 
> fallback?
I thought we could get rid of the memcpy32 variants. Where do we need
memcpy32_* where memcpy16 wouldn't work?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |