Messages in this thread Patch in this message | | | From | NeilBrown <> | Date | Tue, 20 Mar 2018 15:00:55 +1100 | Subject | [PATCH] MIPS: ralink: fix booting on mt7621 |
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Since commit 3af5a67c86a3 ("MIPS: Fix early CM probing") the MT7621 has not been able to boot.
This patched caused mips_cm_probe() to be called before mt7621.c::proc_soc_init().
prom_soc_init() has a comment explaining that mips_cm_probe() "wipes out the bootloader config" and means that configuration registers are no longer available. It has some code to re-enable this config.
Before this re-enable code is run, the sysc register cannot be read, so when SYSC_REG_CHIP_NAME0 is read, a garbage value is returned and panic() is called.
If we move the config-repair code to the top of prom_soc_init(), the registers can be read and boot can proceed.
Fixes: 3af5a67c86a3 ("MIPS: Fix early CM probing") Signed-off-by: NeilBrown <neil@brown.name> --- arch/mips/ralink/mt7621.c | 41 +++++++++++++++++++++-------------------- 1 file changed, 21 insertions(+), 20 deletions(-)
diff --git a/arch/mips/ralink/mt7621.c b/arch/mips/ralink/mt7621.c index 1b274742077d..5a1b19bebd5b 100644 --- a/arch/mips/ralink/mt7621.c +++ b/arch/mips/ralink/mt7621.c @@ -170,6 +170,27 @@ void prom_soc_init(struct ralink_soc_info *soc_info) u32 n1; u32 rev; + /* Early detection of CMP support */ + mips_cm_probe(); + mips_cpc_probe(); + + if (mips_cps_numiocu(0)) { + /* + * mips_cm_probe() wipes out bootloader + * config for CM regions and we have to configure them + * again. This SoC cannot talk to pamlbus devices + * witout proper iocu region set up. + * + * FIXME: it would be better to do this with values + * from DT, but we need this very early because + * without this we cannot talk to pretty much anything + * including serial. + */ + write_gcr_reg0_base(MT7621_PALMBUS_BASE); + write_gcr_reg0_mask(~MT7621_PALMBUS_SIZE | + CM_GCR_REGn_MASK_CMTGT_IOCU0); + } + n0 = __raw_readl(sysc + SYSC_REG_CHIP_NAME0); n1 = __raw_readl(sysc + SYSC_REG_CHIP_NAME1); @@ -194,26 +215,6 @@ void prom_soc_init(struct ralink_soc_info *soc_info) rt2880_pinmux_data = mt7621_pinmux_data; - /* Early detection of CMP support */ - mips_cm_probe(); - mips_cpc_probe(); - - if (mips_cps_numiocu(0)) { - /* - * mips_cm_probe() wipes out bootloader - * config for CM regions and we have to configure them - * again. This SoC cannot talk to pamlbus devices - * witout proper iocu region set up. - * - * FIXME: it would be better to do this with values - * from DT, but we need this very early because - * without this we cannot talk to pretty much anything - * including serial. - */ - write_gcr_reg0_base(MT7621_PALMBUS_BASE); - write_gcr_reg0_mask(~MT7621_PALMBUS_SIZE | - CM_GCR_REGn_MASK_CMTGT_IOCU0); - } if (!register_cps_smp_ops()) return; -- 2.14.0.rc0.dirty [unhandled content-type:application/pgp-signature]
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