From: Dmitry Osipenko digetx@gmail.com
[ Upstream commit b6e1fd17a38bd1d97c11d69fd3207b3ef9bfa4b3 ]
This fixes splats like the one below if CONFIG_DEBUG_ATOMIC_SLEEP=y and machine (Tegra30) booted with SMP=n or all secondary CPU's are put offline. Locking isn't needed because it protects atomic operation.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:254 in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0 CPU: 0 PID: 0 Comm: swapper/0 Tainted: G C 4.18.0-next-20180821-00180-gc3ebb6544e44-dirty #823 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) [<c01134f4>] (unwind_backtrace) from [<c010db2c>] (show_stack+0x20/0x24) [<c010db2c>] (show_stack) from [<c0bd0f3c>] (dump_stack+0x94/0xa8) [<c0bd0f3c>] (dump_stack) from [<c0151df8>] (___might_sleep+0x13c/0x174) [<c0151df8>] (___might_sleep) from [<c0151ea0>] (__might_sleep+0x70/0xa8) [<c0151ea0>] (__might_sleep) from [<c0bec2b8>] (mutex_lock+0x2c/0x70) [<c0bec2b8>] (mutex_lock) from [<c0589844>] (tegra_powergate_is_powered+0x44/0xa8) [<c0589844>] (tegra_powergate_is_powered) from [<c0581a60>] (tegra30_cpu_rail_off_ready+0x30/0x74) [<c0581a60>] (tegra30_cpu_rail_off_ready) from [<c0122244>] (tegra30_idle_lp2+0xa0/0x108) [<c0122244>] (tegra30_idle_lp2) from [<c0853438>] (cpuidle_enter_state+0x140/0x540) [<c0853438>] (cpuidle_enter_state) from [<c08538a4>] (cpuidle_enter+0x40/0x4c) [<c08538a4>] (cpuidle_enter) from [<c01595e0>] (call_cpuidle+0x30/0x48) [<c01595e0>] (call_cpuidle) from [<c01599f8>] (do_idle+0x238/0x28c) [<c01599f8>] (do_idle) from [<c0159d28>] (cpu_startup_entry+0x28/0x2c) [<c0159d28>] (cpu_startup_entry) from [<c0be76c8>] (rest_init+0xd8/0xdc) [<c0be76c8>] (rest_init) from [<c1200f50>] (start_kernel+0x41c/0x430)
Signed-off-by: Dmitry Osipenko digetx@gmail.com Acked-by: Jon Hunter jonathanh@nvidia.com Signed-off-by: Thierry Reding treding@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/soc/tegra/pmc.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c index ed71a4c9c8b2..4b452f36f054 100644 --- a/drivers/soc/tegra/pmc.c +++ b/drivers/soc/tegra/pmc.c @@ -524,16 +524,10 @@ EXPORT_SYMBOL(tegra_powergate_power_off); */ int tegra_powergate_is_powered(unsigned int id) { - int status; - if (!tegra_powergate_is_valid(id)) return -EINVAL;
- mutex_lock(&pmc->powergates_lock); - status = tegra_powergate_state(id); - mutex_unlock(&pmc->powergates_lock); - - return status; + return tegra_powergate_state(id); }
/**