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author | Matt Redfearn <matt.redfearn@mips.com> | 2018-02-20 10:58:16 +0100 |
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committer | James Hogan <jhogan@kernel.org> | 2018-03-09 14:53:26 +0100 |
commit | b2ed33a895676738dfad11cedcba1e3a0a8b6203 (patch) | |
tree | a9014cce241b25f4822bf2f3301194d4b651eb44 /fs/fat | |
parent | MIPS: VDSO: Replace __mips_isa_rev with MIPS_ISA_REV (diff) | |
download | linux-b2ed33a895676738dfad11cedcba1e3a0a8b6203.tar.xz linux-b2ed33a895676738dfad11cedcba1e3a0a8b6203.zip |
MIPS: pm-cps: Block system suspend when a JTAG probe is present
If a JTAG probe is connected to a MIPS cluster, then the CPC detects it
and latches the CPC.STAT_CONF.EJTAG_PROBE bit to 1. While set,
attempting to send a power-down command to a core will be blocked, and
the CPC will instead send the core to clock-off state. This can
interfere with systems fully entering a low power state where all cores,
CM, GIC, etc are powered down.
Detect that a JTAG probe is / has been connected to the cluster and
block the suspend attempt.
Attempting to suspend the system while a JTAG probe is connected now
yields:
# echo mem > /sys/power/state
[ 11.654000] PM: Syncing filesystems ... done.
[ 11.658000] JTAG probe is connected - abort suspend
-sh: echo: write error: Operation not permitted
#
To restore suspend, the JTAG probe should be disconnected or put into
quiescent state. Platform code can then clear the
CPC.STAT_CONF.EJTAG_PROBE bit.
Reported-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18641/
Signed-off-by: James Hogan <jhogan@kernel.org>
Diffstat (limited to 'fs/fat')
0 files changed, 0 insertions, 0 deletions