diff options
| author | Hauke Mehrtens <hauke@hauke-m.de> | 2012-10-03 15:34:17 +0400 |
|---|---|---|
| committer | John Crispin <blogic@openwrt.org> | 2012-11-09 14:37:17 +0400 |
| commit | c47cc20ca53e792938556aa29103fa889ce0d858 (patch) | |
| tree | 55182513e1ffc244339cc41ba5513519bc095d1c /arch/mips | |
| parent | d3dce3d676373b1519546721ee5f3a8c613f40f5 (diff) | |
| download | linux-c47cc20ca53e792938556aa29103fa889ce0d858.tar.xz | |
MIPS: BCM47XX: improve memory size detection
The memory size is detected by finding a place where it repeats in
memory. Currently we are just checking when the function prom_init is
seen again, but it is better to check for a bigger part of the memory
to decrease the chance of wrong results.
This should fix a problem we saw in OpenWrt, where the detected
available memory decreed on some devices when doing a soft reboot.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4362
Signed-off-by: John Crispin <blogic@openwrt.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/bcm47xx/prom.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/mips/bcm47xx/prom.c b/arch/mips/bcm47xx/prom.c index 22258a4c652b..8c155afb1299 100644 --- a/arch/mips/bcm47xx/prom.c +++ b/arch/mips/bcm47xx/prom.c @@ -1,6 +1,7 @@ /* * Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org> * Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net> + * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the @@ -128,6 +129,7 @@ static __init void prom_init_mem(void) { unsigned long mem; unsigned long max; + unsigned long off; struct cpuinfo_mips *c = ¤t_cpu_data; /* Figure out memory size by finding aliases. @@ -145,15 +147,15 @@ static __init void prom_init_mem(void) * max contains the biggest possible address supported by the platform. * If the method wants to try something above we assume 128MB ram. */ - max = ((unsigned long)(prom_init) | ((128 << 20) - 1)); + off = (unsigned long)prom_init; + max = off | ((128 << 20) - 1); for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) { - if (((unsigned long)(prom_init) + mem) > max) { + if ((off + mem) > max) { mem = (128 << 20); printk(KERN_DEBUG "assume 128MB RAM\n"); break; } - if (*(unsigned long *)((unsigned long)(prom_init) + mem) == - *(unsigned long *)(prom_init)) + if (!memcmp(prom_init, prom_init + mem, 32)) break; } |