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[MIPS] Save write-only Config.OD from being clobbered

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Save the Config.OD bit from being clobbered by coherency_setup(). This
bit, when set, fixes various errata in the early steppings of Au1x00
SOCs.  Unfortunately, the bit was write-only on the most early of them.
In addition, also restore the bit after a wakeup from sleep.
    
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Sergei Shtylyov 2006-05-26 19:44:54 +04:00 committed by Ralf Baechle
parent cac4bcbce0
commit 9370b35175
2 changed files with 39 additions and 0 deletions
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5
arch/mips/au1000/common/sleeper.S
View file

@ -112,6 +112,11 @@ sdsleep:
mtc0 k0, CP0_PAGEMASK
lw k0, 0x14(sp)
mtc0 k0, CP0_CONFIG
/* We need to catch the ealry Alchemy SOCs with
* the write-only Config[OD] bit and set it back to one...
*/
jal au1x00_fixup_config_od
lw $1, PT_R1(sp)
lw $2, PT_R2(sp)
lw $3, PT_R3(sp)

34
arch/mips/mm/c-r4k.c
View file

@ -1161,6 +1161,31 @@ static void __init setup_scache(void)
c->options |= MIPS_CPU_SUBSET_CACHES;
}
void au1x00_fixup_config_od(void)
{
/*
* c0_config.od (bit 19) was write only (and read as 0)
* on the early revisions of Alchemy SOCs. It disables the bus
* transaction overlapping and needs to be set to fix various errata.
*/
switch (read_c0_prid()) {
case 0x00030100: /* Au1000 DA */
case 0x00030201: /* Au1000 HA */
case 0x00030202: /* Au1000 HB */
case 0x01030200: /* Au1500 AB */
/*
* Au1100 errata actually keeps silence about this bit, so we set it
* just in case for those revisions that require it to be set according
* to arch/mips/au1000/common/cputable.c
*/
case 0x02030200: /* Au1100 AB */
case 0x02030201: /* Au1100 BA */
case 0x02030202: /* Au1100 BC */
set_c0_config(1 << 19);
break;
}
}
static inline void coherency_setup(void)
{
change_c0_config(CONF_CM_CMASK, CONF_CM_DEFAULT);
@ -1181,6 +1206,15 @@ static inline void coherency_setup(void)
case CPU_R4400MC:
clear_c0_config(CONF_CU);
break;
/*
* We need to catch the ealry Alchemy SOCs with
* the write-only co_config.od bit and set it back to one...
*/
case CPU_AU1000: /* rev. DA, HA, HB */
case CPU_AU1100: /* rev. AB, BA, BC ?? */
case CPU_AU1500: /* rev. AB */
au1x00_fixup_config_od();
break;
}
}