[U-Boot] Resubmit : [PATCH] Correct ARM Versatile Timer Initialization

[Peter Pearse]

> -----Original Message-----
> From: Gururaja Hebbar K R [mailto:gururajakr at sanyo.co.in] 
> Sent: 12 August 2008 03:57
> To: Jean-Christophe PLAGNIOL-VILLARD
> Cc: u-boot at lists.denx.de; wd at denx.de; Peter Pearse
> Subject: RE: Resubmit : [PATCH] Correct ARM Versatile Timer 
> Initialization
> 
>  
> Hi,
> 
> > according to datasheet for the register TimerXControl
> > 
> > we are supposed to not modify the bits [31:8] and [4]
> > 
> > so we are suppose to read the register and modify only the others 
> > register.
> 
> Does this mean i need to resend the earlier patch. Writing 00 
> to these bits ( 31:8 & 4) is undefined. 

Generally, in ARM terminology, one should avoid writing values where writing
a value or bit is undefined.
"Undefined" implies, not that there is no result, but that the outcome is
not defined by the specification.
Hence it is good practice to read/change/write registers with undefined
bits, or bits where writing is undefined.
This is especially important with bits defined as such in ARM TRMs since
different ARM customers may implement
the ARM IP in different ways i.e writing a value to such bits may have
different results in different implementations
and or versions of the hardware.

> 
> So i think this will not make any problems. 
> 
> anyone could you please update me about the status of this 
> patch. if not accessible, i will change & resend
> 
> Regards
> Gururaja
>