Problem with sram size on OMAP1611 (OSK)

[Tim Bird]

Santosh,

I just tried the latest kernel (well, v2.6.36), and found a problem
that bisected to the following commit:

commit e546f21b4b7af012d9f18edad6237339adfeb681
Author: Santosh Shilimkar <santosh.shilimkar at ti.com>
Date:   Fri Sep 24 07:19:49 2010 +0100

    ARM: 6408/1: omap: Map only available sram memory

I am testing Linux on an OSK board (with an OMAP1611),
and the above commmit causes the machine to hang.
I isolated the problem to the sram length.  The commit
above changes it to a value detected in omap_detect_sram(),
but when this value is used, my OSK hangs on boot.

Below is the hack I used to work around this.  I'm not sure
what the problem is, but I'd be happy to provide more information
or try other things, to fix support for omap1611 in mainline.
I tried putting the 1024 * 1024 value into omap_detect_sram(),
with no luck.  There's some additional processing there which
might alter the value.  Or perhaps the current value there
for omap_sram_size on a 1611 is just wrong.

diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c
index 10b3b4c..d4ba4fa 100644
--- a/arch/arm/plat-omap/sram.c
+++ b/arch/arm/plat-omap/sram.c
@@ -236,6 +236,8 @@ void __init omap_map_sram(void)
        base = ROUND_DOWN(base, PAGE_SIZE);
        omap_sram_io_desc[0].pfn = __phys_to_pfn(base);
        omap_sram_io_desc[0].length = ROUND_DOWN(omap_sram_size, PAGE_SIZE);
+       if (cpu_is_omap1611())
+               omap_sram_io_desc[0].length = 1024 * 1024;
        iotable_init(omap_sram_io_desc, ARRAY_SIZE(omap_sram_io_desc));

        printk(KERN_INFO "SRAM: Mapped pa 0x%08lx to va 0x%08lx size: 0x%lx\n",

Regards,
 -- Tim

=============================
Tim Bird
Architecture Group Chair, CE Linux Forum
Senior Staff Engineer, Sony Network Entertainment
=============================