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author | NeilBrown <neil@brown.name> | 2018-03-21 14:02:10 +1100 |
---|---|---|
committer | James Hogan <jhogan@kernel.org> | 2018-03-22 00:06:30 +0000 |
commit | a63d706ea719190a79a6c769e898f70680044d3e (patch) | |
tree | 8a45b4e92f371322614cac40d06308b8c22ff8e2 /arch | |
parent | 891731f6a5dbe508d12443175a7e166a2fba616a (diff) | |
download | linux-stable-a63d706ea719190a79a6c769e898f70680044d3e.tar.gz linux-stable-a63d706ea719190a79a6c769e898f70680044d3e.tar.bz2 linux-stable-a63d706ea719190a79a6c769e898f70680044d3e.zip |
MIPS: ralink: Fix booting on MT7621
Since commit 3af5a67c86a3 ("MIPS: Fix early CM probing") the MT7621 has
not been able to boot.
This commit 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.
Very occasionally, the first register read after the reconfiguration
returns garbage, so add a call to __sync().
Fixes: 3af5a67c86a3 ("MIPS: Fix early CM probing")
Signed-off-by: NeilBrown <neil@brown.name>
Reviewed-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: John Crispin <john@phrozen.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.5+
Patchwork: https://patchwork.linux-mips.org/patch/18859/
Signed-off-by: James Hogan <jhogan@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/mips/ralink/mt7621.c | 42 |
1 files changed, 22 insertions, 20 deletions
diff --git a/arch/mips/ralink/mt7621.c b/arch/mips/ralink/mt7621.c index 1b274742077d..d2718de60b9b 100644 --- a/arch/mips/ralink/mt7621.c +++ b/arch/mips/ralink/mt7621.c @@ -170,6 +170,28 @@ 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); + __sync(); + } + n0 = __raw_readl(sysc + SYSC_REG_CHIP_NAME0); n1 = __raw_readl(sysc + SYSC_REG_CHIP_NAME1); @@ -194,26 +216,6 @@ 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; |