Re: [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma

[Alexandre Belloni]

On 02/04/2018 at 22:23:17 +0200, Peter Rosin wrote:
> >> No, but did it again and checked, see transcript below.
> > 
> > I don't use devmem2. Is 'readback' information accurate or is it
> > always what's been written? Because when you write 0x33 to 0xFFFFECBC,
> > 0x33 is read back, but just after that, when you read it again it's 0.
> 
> Looking at the devmem2 source, it seems very likely that the compiler
> optimizes out the read and thus outputs what has been written.
> 

At least on x86, it is not optimized out.


-- 
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com