[U-Boot] [PATCH 5/5] 85xx: enable the auto self refresh for wake up ARP

Liu Dave DaveLiu at freescale.com
Fri Nov 21 13:20:57 CET 2008


 

> -----Original Message-----
> From: Kumar Gala [mailto:galak at kernel.crashing.org] 
> Sent: Friday, November 21, 2008 7:43 PM
> To: Liu Dave-R63238
> Cc: u-boot at lists.denx.de
> Subject: Re: [U-Boot] [PATCH 5/5] 85xx: enable the auto self 
> refresh for wake up ARP
> 
> 
> On Nov 21, 2008, at 2:31 AM, Dave Liu wrote:
> 
> > The wake up ARP feature need use the memory to process
> > wake up packet, we enable auto self refresh to support it.
> >
> > Signed-off-by: Dave Liu <daveliu at freescale.com>
> > ---
> > board/freescale/mpc8536ds/ddr.c |    6 ++++++
> > 1 files changed, 6 insertions(+), 0 deletions(-)
> >
> > diff --git a/board/freescale/mpc8536ds/ddr.c b/board/freescale/ 
> > mpc8536ds/ddr.c
> > index 3135d6d..2bad787 100644
> > --- a/board/freescale/mpc8536ds/ddr.c
> > +++ b/board/freescale/mpc8536ds/ddr.c
> > @@ -79,4 +79,10 @@ void 
> fsl_ddr_board_options(memctl_options_t *popts,
> > 	 *	- number of DIMMs installed
> > 	 */
> > 	popts->half_strength_driver_enable = 0;
> > +
> > +	/*
> > +	 * For wake up arp feature, we need enable auto self refresh
> > +	 */
> > +	popts->auto_self_refresh_en = 1;
> > +	popts->sr_it = 0x6;
> 
> any reason we picked 6?


That is balance for performance and respond time.
the 6 stand for 3ms time (3ns MCLK)


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