From 1dd7def0b5d7d0464991640687fc85c143b3c850 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Sat, 18 Jul 2009 17:25:30 +0200 Subject: [PATCH] Staging: meilhaus: convert nested spin_lock_irqsave to spin_lock If spin_lock_irqsave is called twice in a row with the same second argument, the interrupt state at the point of the second call overwrites the value saved by the first call. Indeed, the second call does not need to save the interrupt state, so it is changed to a simple spin_lock. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @@ expression lock1,lock2; expression flags; @@ *spin_lock_irqsave(lock1,flags) ... when != flags *spin_lock_irqsave(lock2,flags) // Signed-off-by: Julia Lawall Cc: David Kiliani Cc: Meilhaus Support Signed-off-by: Greg Kroah-Hartman --- drivers/staging/meilhaus/me4600_ai.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/staging/meilhaus/me4600_ai.c b/drivers/staging/meilhaus/me4600_ai.c index e496d0c8d484..fd9daa942fb3 100644 --- a/drivers/staging/meilhaus/me4600_ai.c +++ b/drivers/staging/meilhaus/me4600_ai.c @@ -760,7 +760,7 @@ static int me4600_ai_io_single_read(me_subdevice_t *subdevice, // Mark that StreamConfig is removed. instance->chan_list_len = 0; - spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags); + spin_lock(instance->ctrl_reg_lock); /// @note Imprtant: Preserve EXT IRQ settings. tmp = inl(instance->ctrl_reg); // Clear FIFOs and dissable interrupts @@ -824,7 +824,7 @@ static int me4600_ai_io_single_read(me_subdevice_t *subdevice, instance->ctrl_reg - instance->reg_base, instance->single_config[channel].ctrl | tmp); - spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags); + spin_unlock(instance->ctrl_reg_lock); if (!(instance->single_config[channel].ctrl & ME4600_AI_CTRL_BIT_EX_TRIG)) { // Software start inl(instance->start_reg); @@ -877,7 +877,7 @@ static int me4600_ai_io_single_read(me_subdevice_t *subdevice, } // Restore settings. - spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags); + spin_lock(instance->ctrl_reg_lock); tmp = inl(instance->ctrl_reg); // Clear FIFOs and dissable interrupts. tmp &= @@ -889,7 +889,7 @@ static int me4600_ai_io_single_read(me_subdevice_t *subdevice, outl(tmp, instance->ctrl_reg); PDEBUG_REG("ctrl_reg outl(0x%lX+0x%lX)=0x%x\n", instance->reg_base, instance->ctrl_reg - instance->reg_base, tmp); - spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags); + spin_unlock(instance->ctrl_reg_lock); spin_unlock_irqrestore(&instance->subdevice_lock, cpu_flags); @@ -1268,7 +1268,7 @@ static int me4600_ai_io_stream_config(me_subdevice_t *subdevice, } instance->status = ai_status_none; - spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags); + spin_lock(instance->ctrl_reg_lock); // Stop all actions. Block all interrupts. Clear (disable) FIFOs. ctrl = ME4600_AI_CTRL_BIT_LE_IRQ_RESET | ME4600_AI_CTRL_BIT_HF_IRQ_RESET | @@ -1290,7 +1290,7 @@ static int me4600_ai_io_stream_config(me_subdevice_t *subdevice, outl(tmp | ctrl, instance->ctrl_reg); PDEBUG_REG("ctrl_reg outl(0x%lX+0x%lX)=0x%x\n", instance->reg_base, instance->ctrl_reg - instance->reg_base, tmp | ctrl); - spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags); + spin_unlock(instance->ctrl_reg_lock); // Write the channel list for (i = 0; i < count; i++) { @@ -1529,7 +1529,7 @@ static int me4600_ai_io_stream_config(me_subdevice_t *subdevice, ctrl |= (ME4600_AI_CTRL_BIT_HF_IRQ | ME4600_AI_CTRL_BIT_SC_IRQ | ME4600_AI_CTRL_BIT_LE_IRQ); //The last IRQ source (ME4600_AI_CTRL_BIT_LE_IRQ) is unused! //Everything is good. Finalize - spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags); + spin_lock(instance->ctrl_reg_lock); tmp = inl(instance->ctrl_reg); //Preserve EXT IRQ and OFFSET settings. Clean other bits. @@ -1541,7 +1541,7 @@ static int me4600_ai_io_stream_config(me_subdevice_t *subdevice, outl(ctrl | tmp, instance->ctrl_reg); PDEBUG_REG("ctrl_reg outl(0x%lX+0x%lX)=0x%x\n", instance->reg_base, instance->ctrl_reg - instance->reg_base, ctrl | tmp); - spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags); + spin_unlock(instance->ctrl_reg_lock); //Set the global parameters end exit. instance->chan_list_len = count; -- 2.30.2