[U-Boot] [RESEND PATCH v2] tegra2: Enable data cache

[Tom Warren]

Simon,

> -----Original Message-----
> From: sjg at google.com [mailto:sjg at google.com] On Behalf Of Simon Glass
> Sent: Wednesday, October 12, 2011 2:13 PM
> To: Anton Staaf
> Cc: U-Boot Mailing List; Tom Warren
> Subject: Re: [U-Boot] [RESEND PATCH v2] tegra2: Enable data cache
> 
> Hi Anton,
> 
> On Wed, Oct 12, 2011 at 10:54 AM, Anton Staaf <robotboy at google.com> wrote:
> > On Tue, Oct 11, 2011 at 5:35 PM, Simon Glass <sjg at chromium.org> wrote:
> >> This enables the data cache on Tegra2 boards.
> >>
> >> As discussed on the list, this is better off in the Tegra2 cpu code than
> in a
> >> particular vendor directory. We should be safe turning on the cache for
> all
> >> Tegra2 boards.
> >
> > I don't think it's safe to turn on caches yet for Tegra.  I have some MMC
> driver
> > fixes I'll send up shortly that deal with unaligned DMA requests that are
> > required before turning on caches.  Without these some MMC
> > transactions just hang.
> 
> Yes that's right since yesterday's merge of MMC into u-boot-arm (prior
> to that there was no working MMC!). Let's hold off applying this patch
> until you are done.
> 

I have to disagree with the 'no working MMC' statement. When I submitted my Tegra2 MMC driver in May, it was working fine on Seaboard (hadn't tested yet on Harmony since mine was dead). At that time, DCACHE was off, so no concurrency issues nor hangs were seen. Wolfgang merged it w/master in mid-July.

Just correcting for the record,

Tom
> Regards,
> Simon
> 
> >
> > Thanks,
> >     Anton
> >
> >> Signed-off-by: Simon Glass <sjg at chromium.org>
> >> ---
> >> Changes in v2:
> >> - Enable caches for all Tegra2 boards instead of just Nvidia ones
> >>
> >>  arch/arm/cpu/armv7/tegra2/board.c |    8 ++++++++
> >>  1 files changed, 8 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/arch/arm/cpu/armv7/tegra2/board.c
> b/arch/arm/cpu/armv7/tegra2/board.c
> >> index 9061d18..a996b88 100644
> >> --- a/arch/arm/cpu/armv7/tegra2/board.c
> >> +++ b/arch/arm/cpu/armv7/tegra2/board.c
> >> @@ -86,3 +86,11 @@ int checkboard(void)
> >>        return 0;
> >>  }
> >>  #endif /* CONFIG_DISPLAY_BOARDINFO */
> >> +
> >> +#ifndef CONFIG_SYS_DCACHE_OFF
> >> +void enable_caches(void)
> >> +{
> >> +       /* Enable D-cache. I-cache is already enabled in start.S */
> >> +       dcache_enable();
> >> +}
> >> +#endif
> >> --
> >> 1.7.3.1
> >>
> >> _______________________________________________
> >> U-Boot mailing list
> >> U-Boot at lists.denx.de
> >> http://lists.denx.de/mailman/listinfo/u-boot
> >>
> >
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