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| author | Tingwei Zhang <tingwei@codeaurora.org> | 2020-09-16 21:17:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-17 18:46:04 +0200 |
| commit | 984f37efa3857dcefa649fbdf64abb94591935c3 (patch) | |
| tree | 8ff0a0a1ac5ff5573f9e5d817afacbb38936beb0 /drivers/platform | |
| parent | coresight: etm4x: Fix issues within reset interface of sysfs (diff) | |
| download | linux-984f37efa3857dcefa649fbdf64abb94591935c3.tar.xz linux-984f37efa3857dcefa649fbdf64abb94591935c3.zip | |
coresight: cti: Write regsiters directly in cti_enable_hw()
Deadlock as below is triggered by one CPU holds drvdata->spinlock
and calls cti_enable_hw(). Smp_call_function_single() is called
in cti_enable_hw() and tries to let another CPU write CTI registers.
That CPU is trying to get drvdata->spinlock in cti_cpu_pm_notify()
and doesn't response to IPI from smp_call_function_single().
[ 988.335937] CPU: 6 PID: 10258 Comm: sh Tainted: G W L
5.8.0-rc6-mainline-16783-gc38daa79b26b-dirty #1
[ 988.346364] Hardware name: Thundercomm Dragonboard 845c (DT)
[ 988.352073] pstate: 20400005 (nzCv daif +PAN -UAO BTYPE=--)
[ 988.357689] pc : smp_call_function_single+0x158/0x1b8
[ 988.362782] lr : smp_call_function_single+0x124/0x1b8
...
[ 988.451638] Call trace:
[ 988.454119] smp_call_function_single+0x158/0x1b8
[ 988.458866] cti_enable+0xb4/0xf8 [coresight_cti]
[ 988.463618] coresight_control_assoc_ectdev+0x6c/0x128 [coresight]
[ 988.469855] coresight_enable+0x1f0/0x364 [coresight]
[ 988.474957] enable_source_store+0x5c/0x9c [coresight]
[ 988.480140] dev_attr_store+0x14/0x28
[ 988.483839] sysfs_kf_write+0x38/0x4c
[ 988.487532] kernfs_fop_write+0x1c0/0x2b0
[ 988.491585] vfs_write+0xfc/0x300
[ 988.494931] ksys_write+0x78/0xe0
[ 988.498283] __arm64_sys_write+0x18/0x20
[ 988.502240] el0_svc_common+0x98/0x160
[ 988.506024] do_el0_svc+0x78/0x80
[ 988.509377] el0_sync_handler+0xd4/0x270
[ 988.513337] el0_sync+0x164/0x180
This change write CTI registers directly in cti_enable_hw().
Config->hw_powered has been checked to be true with spinlock holded.
CTI is powered and can be programmed until spinlock is released.
Fixes: 6a0953ce7de9 ("coresight: cti: Add CPU idle pm notifer to CTI devices")
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
[Re-ordered variable declaration]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200916191737.4001561-10-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/platform')
0 files changed, 0 insertions, 0 deletions