[U-Boot] [PATCH] pxa: Disable dcache on palmld, palmtc, zipitz2

Marek Vasut marex at denx.de
Mon Nov 5 23:59:45 CET 2012


Dear Simon Glass,

> Hi,
> 
> On Wed, Oct 31, 2012 at 9:52 AM, Tom Warren <TWarren at nvidia.com> wrote:
> > Marek,
> > 
> >> -----Original Message-----
> >> From: Marek Vasut [mailto:marex at denx.de]
> >> Sent: Wednesday, October 31, 2012 9:41 AM
> >> To: Tom Rini
> >> Cc: Simon Glass; U-Boot Mailing List; Tom Warren
> >> Subject: Re: [PATCH] pxa: Disable dcache on palmld, palmtc, zipitz2
> >> 
> >> Dear Tom Rini,
> >> 
> >> > On 10/31/12 04:55, Marek Vasut wrote:
> >> > > Dear Simon Glass,
> >> > > 
> >> > >> These platforms don't include dcache support. Define
> >> > >> CONFIG_SYS_DCACHE_OFF so that functions don't try to call
> >> > >> non-existent routines like flush_dcache_range().
> >> > >> 
> >> > >> Signed-off-by: Simon Glass <sjg at chromium.org>
> >> > > 
> >> > > Is that needed? Why not fix PXA by defining stub cache routines ?
> >> > 
> >> > Adding stubs sounds more like a work-around than disabling support
> >> > that we won't have to me.
> >> 
> >> Yes, but then, the stubs will be optimized out.
> >> 
> >> I see using CONFIG_SYS_DCACHE_OFF being abused here. Every platform
> >> should implement at least cache operations stubs, then it'd be valid to
> >> use CONFIG_SYS_DCACHE_OFF to indicate the cache shall always be off.
> >> But the code would at least compile and work with CONFIG_SYS_DCACHE_OFF
> >> enabled or disabled.
> >> 
> >> We might eventually even be able to weed out this CONFIG_SYS_DCACHE_OFF
> >> option.
> > 
> > You are the PXA custodian, according to the wiki. Simon's fix is to get
> > the PXA boards that use LCD to compile OK with the Tegra LCD cache flush
> > changes that he implemented. I think it contains the appropriate change
> > to get those builds working, which is all he's obligated to do.
> > 
> > If you want stubs written for those boards, why don't you do it, since it
> > affects the boards you are responsible for? It seems to me that it's
> > more in your bailiwick than Simon's - as you state, every platform
> > should implement cache stubs, and these are your platforms.
> 
> Is that the final word? If so, Tom Warren should be able to pull this
> through. If not, Marek are you going to send a patch to replace this
> patch? If that is coming soon, I suggest we wait a few days. If not,
> then we can perhaps take this patch and then Marek can clean up later.

Just apply this. PXA is mostly dead anyway.

Best regards,
Marek Vasut


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