[PATCH 5.3 009/135] clocksource/drivers/mediatek: Fix error handling

Greg Kroah-Hartman
2019-12-03T22:41:12Z

From: Fabien Parent <fparent@baylibre.com>

[ Upstream commit 41d49e7939de5ec532d86494185b2ca2e99c848a ]

When timer_of_init fails, it cleans up after itself by undoing
everything it did during the initialization function.

mtk_syst_init and mtk_gpt_init both call timer_of_cleanup if
timer_of_init fails. timer_of_cleanup try to release the resource
taken. Since these resources have already been cleaned up by
timer_of_init, we end up getting a few warnings printed:

[ 0.001935] WARNING: CPU: 0 PID: 0 at __clk_put+0xe8/0x128
[ 0.002650] Modules linked in:
[ 0.003058] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.67+ #1
[ 0.003852] Hardware name: MediaTek MT8183 (DT)
[ 0.004446] pstate: 20400085 (nzCv daIf +PAN -UAO)
[ 0.005073] pc : __clk_put+0xe8/0x128
[ 0.005555] lr : clk_put+0xc/0x14
[ 0.005988] sp : ffffff80090b3ea0
[ 0.006422] x29: ffffff80090b3ea0 x28: 0000000040e20018
[ 0.007121] x27: ffffffc07bfff780 x26: 0000000000000001
[ 0.007819] x25: ffffff80090bda80 x24: ffffff8008ec5828
[ 0.008517] x23: ffffff80090bd000 x22: ffffff8008d8b2e8
[ 0.009216] x21: 0000000000000001 x20: fffffffffffffdfb
[ 0.009914] x19: ffffff8009166180 x18: 00000000002bffa8
[ 0.010612] x17: ffffffc012996980 x16: 0000000000000000
[ 0.011311] x15: ffffffbf004a6800 x14: 3536343038393334
[ 0.012009] x13: 2079726576652073 x12: 7eb9c62c5c38f100
[ 0.012707] x11: ffffff80090b3ba0 x10: ffffff80090b3ba0
[ 0.013405] x9 : 0000000000000004 x8 : 0000000000000040
[ 0.014103] x7 : ffffffc079400270 x6 : 0000000000000000
[ 0.014801] x5 : ffffffc079400248 x4 : 0000000000000000
[ 0.015499] x3 : 0000000000000000 x2 : 0000000000000000
[ 0.016197] x1 : ffffff80091661c0 x0 : fffffffffffffdfb
[ 0.016896] Call trace:
[ 0.017218] __clk_put+0xe8/0x128
[ 0.017654] clk_put+0xc/0x14
[ 0.018048] timer_of_cleanup+0x60/0x7c
[ 0.018551] mtk_syst_init+0x8c/0x9c
[ 0.019020] timer_probe+0x6c/0xe0
[ 0.019469] time_init+0x14/0x44
[ 0.019893] start_kernel+0x2d0/0x46c
[ 0.020378] ---[ end trace 8c1efabea1267649 ]---
[ 0.020982] ------------[ cut here ]------------
[ 0.021586] Trying to vfree() nonexistent vm area ((____ptrval____))
[ 0.022427] WARNING: CPU: 0 PID: 0 at __vunmap+0xd0/0xd8
[ 0.023119] Modules linked in:
[ 0.023524] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.19.67+ #1
[ 0.024498] Hardware name: MediaTek MT8183 (DT)
[ 0.025091] pstate: 60400085 (nZCv daIf +PAN -UAO)
[ 0.025718] pc : __vunmap+0xd0/0xd8
[ 0.026176] lr : __vunmap+0xd0/0xd8
[ 0.026632] sp : ffffff80090b3e90
[ 0.027066] x29: ffffff80090b3e90 x28: 0000000040e20018
[ 0.027764] x27: ffffffc07bfff780 x26: 0000000000000001
[ 0.028462] x25: ffffff80090bda80 x24: ffffff8008ec5828
[ 0.029160] x23: ffffff80090bd000 x22: ffffff8008d8b2e8
[ 0.029858] x21: 0000000000000000 x20: 0000000000000000
[ 0.030556] x19: ffffff800800d000 x18: 00000000002bffa8
[ 0.031254] x17: 0000000000000000 x16: 0000000000000000
[ 0.031952] x15: ffffffbf004a6800 x14: 3536343038393334
[ 0.032651] x13: 2079726576652073 x12: 7eb9c62c5c38f100
[ 0.033349] x11: ffffff80090b3b40 x10: ffffff80090b3b40
[ 0.034047] x9 : 0000000000000005 x8 : 5f5f6c6176727470
[ 0.034745] x7 : 5f5f5f5f28282061 x6 : ffffff80091c86ef
[ 0.035443] x5 : ffffff800852b690 x4 : 0000000000000000
[ 0.036141] x3 : 0000000000000002 x2 : 0000000000000002
[ 0.036839] x1 : 7eb9c62c5c38f100 x0 : 7eb9c62c5c38f100
[ 0.037536] Call trace:
[ 0.037859] __vunmap+0xd0/0xd8
[ 0.038271] vunmap+0x24/0x30
[ 0.038664] __iounmap+0x2c/0x34
[ 0.039088] timer_of_cleanup+0x70/0x7c
[ 0.039591] mtk_syst_init+0x8c/0x9c
[ 0.040060] timer_probe+0x6c/0xe0
[ 0.040507] time_init+0x14/0x44
[ 0.040932] start_kernel+0x2d0/0x46c

This commit remove the calls to timer_of_cleanup when timer_of_init
fails since it is unnecessary and actually cause warnings to be printed.

Fixes: a0858f937960 ("mediatek: Convert the driver to timer-of")
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/linux-arm-kernel/20190919191315.25190-1-fparent@baylibre.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clocksource/timer-mediatek.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/clocksource/timer-mediatek.c b/drivers/clocksource/timer-mediatek.c
index a562f491b0f8d..9318edcd89635 100644
--- a/drivers/clocksource/timer-mediatek.c
+++ b/drivers/clocksource/timer-mediatek.c
@@ -268,15 +268,12 @@ static int __init mtk_syst_init(struct device_node *node)

ret = timer_of_init(node, &to);
if (ret)
- goto err;
+ return ret;

clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
TIMER_SYNC_TICKS, 0xffffffff);

return 0;
-err:
- timer_of_cleanup(&to);
- return ret;
}

static int __init mtk_gpt_init(struct device_node *node)
@@ -293,7 +290,7 @@ static int __init mtk_gpt_init(struct device_node *node)

ret = timer_of_init(node, &to);
if (ret)
- goto err;
+ return ret;

/* Configure clock source */
mtk_gpt_setup(&to, TIMER_CLK_SRC, GPT_CTRL_OP_FREERUN);
@@ -311,9 +308,6 @@ static int __init mtk_gpt_init(struct device_node *node)
mtk_gpt_enable_irq(&to, TIMER_CLK_EVT);

return 0;
-err:
- timer_of_cleanup(&to);
- return ret;
}
TIMER_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer", mtk_gpt_init);
TIMER_OF_DECLARE(mtk_mt6765, "mediatek,mt6765-timer", mtk_syst_init);
--
2.20.1