Unverified Commit 2859b178 authored by Olivier Moysan's avatar Olivier Moysan Committed by Mark Brown
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ASoC: stm32: spdifrx: fix inconsistent lock state 



In current spdifrx driver locks may be requested as follows:
- request lock on iec capture control, when starting synchronization.
- request lock in interrupt context, when spdifrx stop is called
from IRQ handler.

Take lock with IRQs disabled, to avoid the possible deadlock.

Lockdep report:
[   74.278059] ================================
[   74.282306] WARNING: inconsistent lock state
[   74.290120] --------------------------------
...
[   74.314373]        CPU0
[   74.314377]        ----
[   74.314381]   lock(&(&spdifrx->lock)->rlock);
[   74.314396]   <Interrupt>
[   74.314400]     lock(&(&spdifrx->lock)->rlock);

Fixes: 03e4d5d5 ("ASoC: stm32: Add SPDIFRX support")

Signed-off-by: default avatarOlivier Moysan <olivier.moysan@st.com>
Link: https://lore.kernel.org/r/20191204154333.7152-2-olivier.moysan@st.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 07d22a9b

sound/soc/stm/stm32_spdifrx.c

+7 −5
Original line number Diff line number Diff line
@@ -320,6 +320,7 @@ static void stm32_spdifrx_dma_ctrl_stop(struct stm32_spdifrx_data *spdifrx) 
static int stm32_spdifrx_start_sync(struct stm32_spdifrx_data *spdifrx)

{

	int cr, cr_mask, imr, ret;

	unsigned long flags;



	/* Enable IRQs */

	imr = SPDIFRX_IMR_IFEIE | SPDIFRX_IMR_SYNCDIE | SPDIFRX_IMR_PERRIE;
@@ -327,7 +328,7 @@ static int stm32_spdifrx_start_sync(struct stm32_spdifrx_data *spdifrx) 
	if (ret)

		return ret;



	spin_lock(&spdifrx->lock);

	spin_lock_irqsave(&spdifrx->lock, flags);



	spdifrx->refcount++;
@@ -362,7 +363,7 @@ static int stm32_spdifrx_start_sync(struct stm32_spdifrx_data *spdifrx) 
				"Failed to start synchronization\n");

	}



	spin_unlock(&spdifrx->lock);

	spin_unlock_irqrestore(&spdifrx->lock, flags);



	return ret;

}
@@ -370,11 +371,12 @@ static int stm32_spdifrx_start_sync(struct stm32_spdifrx_data *spdifrx) 
static void stm32_spdifrx_stop(struct stm32_spdifrx_data *spdifrx)

{

	int cr, cr_mask, reg;

	unsigned long flags;



	spin_lock(&spdifrx->lock);

	spin_lock_irqsave(&spdifrx->lock, flags);



	if (--spdifrx->refcount) {

		spin_unlock(&spdifrx->lock);

		spin_unlock_irqrestore(&spdifrx->lock, flags);

		return;

	}
@@ -393,7 +395,7 @@ static void stm32_spdifrx_stop(struct stm32_spdifrx_data *spdifrx) 
	regmap_read(spdifrx->regmap, STM32_SPDIFRX_DR, &reg);

	regmap_read(spdifrx->regmap, STM32_SPDIFRX_CSR, &reg);



	spin_unlock(&spdifrx->lock);

	spin_unlock_irqrestore(&spdifrx->lock, flags);

}



static int stm32_spdifrx_dma_ctrl_register(struct device *dev,

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