[PATCH] dmaengine: edma: No need save/restore interrupt flags during spin_lock in IRQ

[Joel Fernandes]

The vchan lock in edma_callback is acquired in hard interrupt context. As
interrupts are already disabled, there's no point in save/restoring interrupt
mask bit or cpsr flags.

Get rid of flags local variable and use spin_lock instead of spin_lock_irqsave.

Signed-off-by: Joel Fernandes <joelf at ti.com>
---
drivers/dma/edma.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 91849aa..25a75e2 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -638,7 +638,6 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
struct edma_chan *echan = data;
struct device *dev = echan->vchan.chan.device->dev;
struct edma_desc *edesc;
- unsigned long flags;
struct edmacc_param p;

edesc = echan->edesc;
@@ -649,7 +648,7 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)

switch (ch_status) {
case EDMA_DMA_COMPLETE:
- spin_lock_irqsave(&echan->vchan.lock, flags);
+ spin_lock(&echan->vchan.lock);

if (edesc) {
if (edesc->cyclic) {
@@ -665,11 +664,11 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
}
}

- spin_unlock_irqrestore(&echan->vchan.lock, flags);
+ spin_unlock(&echan->vchan.lock);

break;
case EDMA_DMA_CC_ERROR:
- spin_lock_irqsave(&echan->vchan.lock, flags);
+ spin_lock(&echan->vchan.lock);

edma_read_slot(EDMA_CHAN_SLOT(echan->slot[0]), &p);

@@ -700,7 +699,7 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
edma_trigger_channel(echan->ch_num);
}

- spin_unlock_irqrestore(&echan->vchan.lock, flags);
+ spin_unlock(&echan->vchan.lock);

break;
default:

[Vinod Koul]

Post by Joel Fernandes
The vchan lock in edma_callback is acquired in hard interrupt context. As
interrupts are already disabled, there's no point in save/restoring interrupt
mask bit or cpsr flags.
Get rid of flags local variable and use spin_lock instead of spin_lock_irqsave.

Applied, thanks
--
~Vinod

Post by Joel Fernandes
Signed-off-by: Joel Fernandes <joelf at ti.com>
---
drivers/dma/edma.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 91849aa..25a75e2 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -638,7 +638,6 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
struct edma_chan *echan = data;
struct device *dev = echan->vchan.chan.device->dev;
struct edma_desc *edesc;
- unsigned long flags;
struct edmacc_param p;
edesc = echan->edesc;
@@ -649,7 +648,7 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
switch (ch_status) {
- spin_lock_irqsave(&echan->vchan.lock, flags);
+ spin_lock(&echan->vchan.lock);
if (edesc) {
if (edesc->cyclic) {
@@ -665,11 +664,11 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
}
}
- spin_unlock_irqrestore(&echan->vchan.lock, flags);
+ spin_unlock(&echan->vchan.lock);
break;
- spin_lock_irqsave(&echan->vchan.lock, flags);
+ spin_lock(&echan->vchan.lock);
edma_read_slot(EDMA_CHAN_SLOT(echan->slot[0]), &p);
@@ -700,7 +699,7 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
edma_trigger_channel(echan->ch_num);
}
- spin_unlock_irqrestore(&echan->vchan.lock, flags);
+ spin_unlock(&echan->vchan.lock);
break;
--
1.7.9.5

--