Re: n900 in next-20170901

[Tony Lindgren]

* Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> [171114 06:34]:
> On Fri, Nov 10, 2017 at 07:36:20AM -0800, Tony Lindgren wrote:
> > * Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> [171110 06:34]:
> > > On Thu, Nov 09, 2017 at 07:26:10PM -0800, Tony Lindgren wrote:
> > > > +#define OMAP34XX_SRAM_PHYS	0x40200000
> > > > +#define OMAP34XX_SRAM_VIRT	0xd0010000
> > > > +#define OMAP34XX_SRAM_SIZE	0x10000
> > > 
> > > For my testing environment, vmalloc address space is started at
> > > roughly 0xe0000000 so 0xd0010000 would not be valid.
> > 
> > Well we can map it anywhere we want, got any preferences?
> 
> My testing environment is a beagle-(xm?) for QEMU. It is configured by
> CONFIG_VMSPLIT_3G=y so kernel address space is started at 0xc0000000.
> And, it has 512 MB memory so 0xc0000000 ~ 0xdff00000 is used for
> direct mapping. See below.
> 
> [    0.000000] Memory: 429504K/522240K available (11264K kernel code,
> 1562K rwdata, 4288K rodata, 2048K init, 405K bss, 27200K reserved,
> 65536K cma-reserved, 0K highmem)
> [    0.000000] Virtual kernel memory layout:
> [    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
> [    0.000000]     fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
> [    0.000000]     vmalloc : 0xe0000000 - 0xff800000   ( 504 MB)
> [    0.000000]     lowmem  : 0xc0000000 - 0xdff00000   ( 511 MB)
> [    0.000000]     pkmap   : 0xbfe00000 - 0xc0000000   (   2 MB)
> [    0.000000]     modules : 0xbf000000 - 0xbfe00000   (  14 MB)
> [    0.000000]       .text : 0xc0208000 - 0xc0e00000   (12256 kB)
> [    0.000000]       .init : 0xc1300000 - 0xc1500000   (2048 kB)
> [    0.000000]       .data : 0xc1500000 - 0xc1686810   (1563 kB)
> [    0.000000]        .bss : 0xc168fc68 - 0xc16f512c   ( 406 kB)
> 
> Therefore, if OMAP34XX_SRAM_VIRT is 0xd0010000, direct mapping is
> broken and the system doesn't work. I guess that we should use more
> stable address like as 0xf0000000.

OK. Let's forget about adding static mappings and my earlier
patches to attempt to fix this. Below is what I now think we should
merge as a fix before merging Joonsoo's patches. Please all review
and test, adding Tero to Cc also.

Regards,

Tony

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