[U-Boot] [PATCH ... resent] Atmel LCD driver GUARDTIME fix

Haavard Skinnemoen haavard.skinnemoen at atmel.com
Tue Jun 23 09:21:38 CEST 2009


Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 08:53 Tue 23 Jun     , Haavard Skinnemoen wrote:
> > Jean-Christophe PLAGNIOL-VILLARD wrote:  
> > > for at91 the GUARD_TIME is 1 and IIRC it's lcd specific  
> > 
> > You just contradicted yourself.  
> at91 boards

Ok, I see.

> > 
> > The Guard time is the number of empty frames (with control signals
> > enabled but no data) to wait before starting to send valid data to the
> > display.
> > 
> > Setting it slightly too high shouldn't make any difference. However,
> > setting it slightly too low may cause strange failures every now and
> > then.  
> for at91 boards it's 1 and I've never seen any problem, same in the kernel
> 
> So I'll prefer to make it optionial and no hardcoded for all boards.

Good point. How about if we turn it into a configuration symbol and
default to 1 if it's unset?

Haavard


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