From 9370b35175ca43fad7d24bc7b391473f3becbee8 Mon Sep 17 00:00:00 2001 From: Sergei Shtylyov Date: Fri, 26 May 2006 19:44:54 +0400 Subject: [MIPS] Save write-only Config.OD from being clobbered 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 Signed-off-by: Ralf Baechle --- arch/mips/au1000/common/sleeper.S | 5 +++++ arch/mips/mm/c-r4k.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/arch/mips/au1000/common/sleeper.S b/arch/mips/au1000/common/sleeper.S index 44dac3b0df3b..683d9da84b66 100644 --- a/arch/mips/au1000/common/sleeper.S +++ b/arch/mips/au1000/common/sleeper.S @@ -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) diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index 6b3541769602..4a43924cd4fc 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -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; } } -- cgit v1.2.3