Aw: Re: RFC on writel and writel_relaxed

[Lino Sanfilippo]

Hi,


> 
> Yeah so that other trick I'm talking about is also used for timing
> accuracy.
> 
> For example, let's say I have a device with a reset bit and the spec
> says the reset bit needs to be set for at least 10us.
> 
> This is wrong:
> 
> 	writel(1, RESET_REG);
> 	usleep(10);
> 	writel(0, RESET_REG);
> 
> Because of write posting, the first write might arrive to the device
> right before the second one.
> 

Does not write posting only concern PCI? This seems to be a different topic. Furthermore
write posting should not include write reordering...

Regards,
Lino