Messages in this thread | | | Date | Fri, 24 May 2013 18:52:54 +0200 | From | Jean-Christophe PLAGNIOL-VILLARD <> | Subject | Re: [PATCH] ARM: at91: Fix: Change internal SRAM memory type to "MT_MEMORY_SO" |
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On 17:40 Fri 24 May , Russell King - ARM Linux wrote: > On Fri, May 24, 2013 at 04:03:22PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote: > > On 12:20 Fri 24 May , Russell King - ARM Linux wrote: > > > On Fri, May 24, 2013 at 07:11:04AM +0000, Yang, Wenyou wrote: > > > > The story is: for sama5d3x with Cortex-A5 core, if not so, when copying > > > > code snippet to the internal SRAM, then jump to run this code, but fail > > > > to run. > > > > > > And that is where your mistake is - you forgot that you're working with > > > a CPU with harvard caches which will require some cache maintanence > > > between copying the code and executing it. > > > > > > You want to look at flush_icache_range() rather than making this memory > > > strongly ordered. > > > > I understand your point but today we map a SRAM as MT_DEVICE > > If you map SRAM as MT_DEVICE then you won't be able to execute code from > it. It needs to be a normal memory mapping.
Yeah that a bug on AT91, by luck it work on armv3/v4 with MT_DEVICE, I should have spot it earlier when cleanning the at91 but did not
That's why Yang change the SRAM mapping as MT_MEMORY_SO
I agree the commit message need to be re-done
Best Regards, J.
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