2022-04-27 11:12:54

by Sasha Levin

Subject: [PATCH AUTOSEL 4.9 1/3] ASoC: wm8731: Disable the regulator when probing fails

From: Zheyu Ma <[email protected]>

[ Upstream commit 92ccbf17eeacf510cf1eed9c252d9332ca24f02d ]

When the driver fails during probing, the driver should disable the
regulator, not just handle it in wm8731_hw_init().

The following log reveals it:

[ 17.812483] WARNING: CPU: 1 PID: 364 at drivers/regulator/core.c:2257 _regulator_put+0x3ec/0x4e0
[ 17.815958] RIP: 0010:_regulator_put+0x3ec/0x4e0
[ 17.824467] Call Trace:
[ 17.824774] <TASK>
[ 17.825040] regulator_bulk_free+0x82/0xe0
[ 17.825514] devres_release_group+0x319/0x3d0
[ 17.825882] i2c_device_probe+0x766/0x940
[ 17.829198] i2c_register_driver+0xb5/0x130

Signed-off-by: Zheyu Ma <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
sound/soc/codecs/wm8731.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c
index 4f9a1eb28120..abe5e77ba171 100644
--- a/sound/soc/codecs/wm8731.c
+++ b/sound/soc/codecs/wm8731.c
@@ -604,7 +604,7 @@ static int wm8731_hw_init(struct device *dev, struct wm8731_priv *wm8731)
ret = wm8731_reset(wm8731->regmap);
if (ret < 0) {
dev_err(dev, "Failed to issue reset: %d\n", ret);
- goto err_regulator_enable;
+ goto err;
}

/* Clear POWEROFF, keep everything else disabled */
@@ -621,10 +621,7 @@ static int wm8731_hw_init(struct device *dev, struct wm8731_priv *wm8731)

regcache_mark_dirty(wm8731->regmap);

-err_regulator_enable:
- /* Regulators will be enabled by bias management */
- regulator_bulk_disable(ARRAY_SIZE(wm8731->supplies), wm8731->supplies);
-
+err:
return ret;
}

@@ -768,21 +765,27 @@ static int wm8731_i2c_probe(struct i2c_client *i2c,
ret = PTR_ERR(wm8731->regmap);
dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
ret);
- return ret;
+ goto err_regulator_enable;
}

ret = wm8731_hw_init(&i2c->dev, wm8731);
if (ret != 0)
- return ret;
+ goto err_regulator_enable;

ret = snd_soc_register_codec(&i2c->dev,
&soc_codec_dev_wm8731, &wm8731_dai, 1);
if (ret != 0) {
dev_err(&i2c->dev, "Failed to register CODEC: %d\n", ret);
- return ret;
+ goto err_regulator_enable;
}

return 0;
+
+err_regulator_enable:
+ /* Regulators will be enabled by bias management */
+ regulator_bulk_disable(ARRAY_SIZE(wm8731->supplies), wm8731->supplies);
+
+ return ret;
}

static int wm8731_i2c_remove(struct i2c_client *client)
--
2.35.1

2022-04-27 11:24:03

by Sasha Levin

Subject: [PATCH AUTOSEL 4.9 2/3] drivers: net: hippi: Fix deadlock in rr_close()

From: Duoming Zhou <[email protected]>

[ Upstream commit bc6de2878429e85c1f1afaa566f7b5abb2243eef ]

There is a deadlock in rr_close(), which is shown below:

(Thread 1) | (Thread 2)
| rr_open()
rr_close() | add_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | rr_timer()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...

We hold rrpriv->lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need rrpriv->lock in position (2) of thread 2.
As a result, rr_close() will block forever.

This patch extracts del_timer_sync() from the protection of
spin_lock_irqsave(), which could let timer handler to obtain
the needed lock.

Signed-off-by: Duoming Zhou <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
drivers/net/hippi/rrunner.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/net/hippi/rrunner.c b/drivers/net/hippi/rrunner.c
index 6f3519123eb6..0e1a422d9567 100644
--- a/drivers/net/hippi/rrunner.c
+++ b/drivers/net/hippi/rrunner.c
@@ -1354,7 +1354,9 @@ static int rr_close(struct net_device *dev)

rrpriv->fw_running = 0;

+ spin_unlock_irqrestore(&rrpriv->lock, flags);
del_timer_sync(&rrpriv->timer);
+ spin_lock_irqsave(&rrpriv->lock, flags);

writel(0, &regs->TxPi);
writel(0, &regs->IpRxPi);
--
2.35.1