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| author | Yifeng Li <tomli@tomli.me> | 2019-02-06 15:07:21 +0800 |
|---|---|---|
| committer | Paul Burton <paul.burton@mips.com> | 2019-02-07 11:50:14 -0800 |
| commit | 8a96669d77897ff3613157bf43f875739205d66d (patch) | |
| tree | 7d8b67fd70f48372307d0499aa27dc11b1335a78 /arch/mips | |
| parent | 2b424cfc69728224fcb5fad138ea7260728e0901 (diff) | |
| download | linux-8a96669d77897ff3613157bf43f875739205d66d.tar.bz2 | |
mips: loongson64: remove unreachable(), fix loongson_poweroff().
On my Yeeloong 8089, I noticed the machine fails to shutdown
properly, and often, the function mach_prepare_reboot() is
unexpectedly executed, thus the machine reboots instead. A
wait loop is needed to ensure the system is in a well-defined
state before going down.
In commit 997e93d4df16 ("MIPS: Hang more efficiently on
halt/powerdown/restart"), a general superset of the wait loop for all
platforms is already provided, so we don't need to implement our own.
This commit simply removes the unreachable() compiler marco after
mach_prepare_reboot(), thus allowing the execution of machine_hang().
My test shows that the machine is now able to shutdown successfully.
Please note that there are two different bugs preventing the machine
from shutting down, another work-in-progress commit is needed to
fix a lockup in cpufreq / i8259 driver, please read Reference, this
commit does not fix that bug.
Reference: https://lkml.org/lkml/2019/2/5/908
Signed-off-by: Yifeng Li <tomli@tomli.me>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable@vger.kernel.org # v4.17+
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/loongson64/common/reset.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/mips/loongson64/common/reset.c b/arch/mips/loongson64/common/reset.c index a60715e11306..b26892ce871c 100644 --- a/arch/mips/loongson64/common/reset.c +++ b/arch/mips/loongson64/common/reset.c @@ -59,7 +59,12 @@ static void loongson_poweroff(void) { #ifndef CONFIG_LEFI_FIRMWARE_INTERFACE mach_prepare_shutdown(); - unreachable(); + + /* + * It needs a wait loop here, but mips/kernel/reset.c already calls + * a generic delay loop, machine_hang(), so simply return. + */ + return; #else void (*fw_poweroff)(void) = (void *)loongson_sysconf.poweroff_addr; |