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authorMarek Szyprowski <m.szyprowski@samsung.com>2019-11-12 11:47:34 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-11-29 12:50:34 +0100
commite1e047ace8cef6d143f38c7d769753f133becbe6 (patch)
tree87280143f36c2fe023db14861951577a67f4dd6c /drivers/devfreq
parent9e7a03233e02afd3ee061e373355f34d7254f1e6 (diff)
downloadlinux-e1e047ace8cef6d143f38c7d769753f133becbe6.tar.bz2
PM / devfreq: Add missing locking while setting suspend_freq
Commit 2abb0d5268ae ("PM / devfreq: Lock devfreq in trans_stat_show") revealed a missing locking while calling devfreq_update_status() function during suspend/resume cycle. Code analysis revealed that devfreq_set_target() function was called without needed locks held for setting device specific suspend_freq if such has been defined. This patch fixes that by adding the needed locking, what fixes following kernel warning on Exynos4412-based OdroidU3 board during system suspend: PM: suspend entry (deep) Filesystems sync: 0.002 seconds Freezing user space processes ... (elapsed 0.001 seconds) done. OOM killer disabled. Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1385 at drivers/devfreq/devfreq.c:204 devfreq_update_status+0xc0/0x188 Modules linked in: CPU: 2 PID: 1385 Comm: rtcwake Not tainted 5.4.0-rc6-next-20191111 #6848 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c0112588>] (unwind_backtrace) from [<c010e070>] (show_stack+0x10/0x14) [<c010e070>] (show_stack) from [<c0afb010>] (dump_stack+0xb4/0xe0) [<c0afb010>] (dump_stack) from [<c01272e0>] (__warn+0xf4/0x10c) [<c01272e0>] (__warn) from [<c01273a8>] (warn_slowpath_fmt+0xb0/0xb8) [<c01273a8>] (warn_slowpath_fmt) from [<c07d105c>] (devfreq_update_status+0xc0/0x188) [<c07d105c>] (devfreq_update_status) from [<c07d2d70>] (devfreq_set_target+0xb0/0x15c) [<c07d2d70>] (devfreq_set_target) from [<c07d3598>] (devfreq_suspend+0x2c/0x64) [<c07d3598>] (devfreq_suspend) from [<c05de0b0>] (dpm_suspend+0xa4/0x57c) [<c05de0b0>] (dpm_suspend) from [<c05def74>] (dpm_suspend_start+0x98/0xa0) [<c05def74>] (dpm_suspend_start) from [<c0195b58>] (suspend_devices_and_enter+0xec/0xc74) [<c0195b58>] (suspend_devices_and_enter) from [<c0196a20>] (pm_suspend+0x340/0x410) [<c0196a20>] (pm_suspend) from [<c019480c>] (state_store+0x6c/0xc8) [<c019480c>] (state_store) from [<c033fc50>] (kernfs_fop_write+0x10c/0x228) [<c033fc50>] (kernfs_fop_write) from [<c02a6d3c>] (__vfs_write+0x30/0x1d0) [<c02a6d3c>] (__vfs_write) from [<c02a9afc>] (vfs_write+0xa4/0x180) [<c02a9afc>] (vfs_write) from [<c02a9d58>] (ksys_write+0x60/0xd8) [<c02a9d58>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xed3d7fa8 to 0xed3d7ff0) ... irq event stamp: 9667 hardirqs last enabled at (9679): [<c0b1e7c4>] _raw_spin_unlock_irq+0x20/0x58 hardirqs last disabled at (9698): [<c0b16a20>] __schedule+0xd8/0x818 softirqs last enabled at (9694): [<c01026fc>] __do_softirq+0x4fc/0x5fc softirqs last disabled at (9719): [<c012fe68>] irq_exit+0x16c/0x170 ---[ end trace 41ac5b57d046bdbc ]--- ------------[ cut here ]------------ Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/devfreq')
-rw-r--r--drivers/devfreq/devfreq.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index f840e61e5a27..425149e8bab0 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -921,7 +921,9 @@ int devfreq_suspend_device(struct devfreq *devfreq)
}
if (devfreq->suspend_freq) {
+ mutex_lock(&devfreq->lock);
ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
+ mutex_unlock(&devfreq->lock);
if (ret)
return ret;
}
@@ -949,7 +951,9 @@ int devfreq_resume_device(struct devfreq *devfreq)
return 0;
if (devfreq->resume_freq) {
+ mutex_lock(&devfreq->lock);
ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
+ mutex_unlock(&devfreq->lock);
if (ret)
return ret;
}