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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Dmitry Osipenko <digetx@gmail.com>,
	Thierry Reding <treding@nvidia.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-tegra@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 24/37] soc/tegra: pmc: Drop locking from tegra_powergate_is_powered()
Date: Fri, 29 Mar 2019 21:30:07 -0400	[thread overview]
Message-ID: <20190330013020.379-24-sashal@kernel.org> (raw)
In-Reply-To: <20190330013020.379-1-sashal@kernel.org>

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 7e9ef3431bea..2422ed56895a 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -521,16 +521,10 @@ 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);
 }
 
 /**
-- 
2.19.1


  parent reply	other threads:[~2019-03-30  1:36 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-30  1:29 [PATCH AUTOSEL 4.14 01/37] gpio: pxa: handle corner case of unprobed device Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 02/37] rsi: improve kernel thread handling to fix kernel panic Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 03/37] 9p: do not trust pdu content for stat item size Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 04/37] 9p locks: add mount option for lock retry interval Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 05/37] f2fs: fix to do sanity check with current segment number Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 06/37] netfilter: xt_cgroup: shrink size of v2 path Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 07/37] serial: uartps: console_setup() can't be placed to init section Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 08/37] powerpc/pseries: Remove prrn_work workqueue Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 09/37] media: au0828: cannot kfree dev before usb disconnect Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 10/37] HID: i2c-hid: override HID descriptors for certain devices Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 11/37] ARM: samsung: Limit SAMSUNG_PM_CHECK config option to non-Exynos platforms Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 12/37] usbip: fix vhci_hcd controller counting Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 13/37] ACPI / SBS: Fix GPE storm on recent MacBookPro's Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 14/37] KVM: nVMX: restore host state in nested_vmx_vmexit for VMFail Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 15/37] compiler.h: update definition of unreachable() Sasha Levin
2019-03-30  1:29 ` [PATCH AUTOSEL 4.14 16/37] cifs: fallback to older infolevels on findfirst queryinfo retry Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 17/37] kernel: hung_task.c: disable on suspend Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 18/37] nvme-pci: fix conflicting p2p resource adds Sasha Levin
2019-04-01 17:37   ` Heitke, Kenneth
2019-04-03 12:57     ` Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 19/37] blk-mq: protect debugfs_create_files() from failures Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 20/37] crypto: sha256/arm - fix crash bug in Thumb2 build Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 21/37] crypto: sha512/arm " Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 22/37] iommu/dmar: Fix buffer overflow during PCI bus notification Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 23/37] kvm: properly check debugfs dentry before using it Sasha Levin
2019-03-30  1:30 ` Sasha Levin [this message]
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 25/37] ext4: prohibit fstrim in norecovery mode Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 26/37] lkdtm: Print real addresses Sasha Levin
2019-03-30  1:30 ` [PATCH AUTOSEL 4.14 27/37] lkdtm: Add tests for NULL pointer dereference Sasha Levin

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