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dmaengine: altera: fix spinlock usage

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Since this lock is acquired in both process and IRQ context, failing to
to disable IRQs when trying to acquire the lock in process context can
lead to deadlocks.

Signed-off-by: Sylvain Lesne <lesne@alse-fr.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Sylvain Lesne 2017-09-18 13:08:01 +02:00 committed by Vinod Koul
parent d9ec46416d
commit edf10919e5
1 changed files with 21 additions and 14 deletions
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35
drivers/dma/altera-msgdma.c
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@ -212,11 +212,12 @@ struct msgdma_device {
static struct msgdma_sw_desc *msgdma_get_descriptor(struct msgdma_device *mdev)
{
struct msgdma_sw_desc *desc;
unsigned long flags;
spin_lock_bh(&mdev->lock);
spin_lock_irqsave(&mdev->lock, flags);
desc = list_first_entry(&mdev->free_list, struct msgdma_sw_desc, node);
list_del(&desc->node);
spin_unlock_bh(&mdev->lock);
spin_unlock_irqrestore(&mdev->lock, flags);
INIT_LIST_HEAD(&desc->tx_list);
@ -306,13 +307,14 @@ static dma_cookie_t msgdma_tx_submit(struct dma_async_tx_descriptor *tx)
struct msgdma_device *mdev = to_mdev(tx->chan);
struct msgdma_sw_desc *new;
dma_cookie_t cookie;
unsigned long flags;
new = tx_to_desc(tx);
spin_lock_bh(&mdev->lock);
spin_lock_irqsave(&mdev->lock, flags);
cookie = dma_cookie_assign(tx);
list_add_tail(&new->node, &mdev->pending_list);
spin_unlock_bh(&mdev->lock);
spin_unlock_irqrestore(&mdev->lock, flags);
return cookie;
}
@ -336,17 +338,18 @@ msgdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
struct msgdma_extended_desc *desc;
size_t copy;
u32 desc_cnt;
unsigned long irqflags;
desc_cnt = DIV_ROUND_UP(len, MSGDMA_MAX_TRANS_LEN);
spin_lock_bh(&mdev->lock);
spin_lock_irqsave(&mdev->lock, irqflags);
if (desc_cnt > mdev->desc_free_cnt) {
spin_unlock_bh(&mdev->lock);
dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev);
return NULL;
}
mdev->desc_free_cnt -= desc_cnt;
spin_unlock_bh(&mdev->lock);
spin_unlock_irqrestore(&mdev->lock, irqflags);
do {
/* Allocate and populate the descriptor */
@ -397,18 +400,19 @@ msgdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
u32 desc_cnt = 0, i;
struct scatterlist *sg;
u32 stride;
unsigned long irqflags;
for_each_sg(sgl, sg, sg_len, i)
desc_cnt += DIV_ROUND_UP(sg_dma_len(sg), MSGDMA_MAX_TRANS_LEN);
spin_lock_bh(&mdev->lock);
spin_lock_irqsave(&mdev->lock, irqflags);
if (desc_cnt > mdev->desc_free_cnt) {
spin_unlock_bh(&mdev->lock);
dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev);
return NULL;
}
mdev->desc_free_cnt -= desc_cnt;
spin_unlock_bh(&mdev->lock);
spin_unlock_irqrestore(&mdev->lock, irqflags);
avail = sg_dma_len(sgl);
@ -566,10 +570,11 @@ static void msgdma_start_transfer(struct msgdma_device *mdev)
static void msgdma_issue_pending(struct dma_chan *chan)
{
struct msgdma_device *mdev = to_mdev(chan);
unsigned long flags;
spin_lock_bh(&mdev->lock);
spin_lock_irqsave(&mdev->lock, flags);
msgdma_start_transfer(mdev);
spin_unlock_bh(&mdev->lock);
spin_unlock_irqrestore(&mdev->lock, flags);
}
/**
@ -634,10 +639,11 @@ static void msgdma_free_descriptors(struct msgdma_device *mdev)
static void msgdma_free_chan_resources(struct dma_chan *dchan)
{
struct msgdma_device *mdev = to_mdev(dchan);
unsigned long flags;
spin_lock_bh(&mdev->lock);
spin_lock_irqsave(&mdev->lock, flags);
msgdma_free_descriptors(mdev);
spin_unlock_bh(&mdev->lock);
spin_unlock_irqrestore(&mdev->lock, flags);
kfree(mdev->sw_desq);
}
@ -682,8 +688,9 @@ static void msgdma_tasklet(unsigned long data)
u32 count;
u32 __maybe_unused size;
u32 __maybe_unused status;
unsigned long flags;
spin_lock(&mdev->lock);
spin_lock_irqsave(&mdev->lock, flags);
/* Read number of responses that are available */
count = ioread32(mdev->csr + MSGDMA_CSR_RESP_FILL_LEVEL);
@ -704,7 +711,7 @@ static void msgdma_tasklet(unsigned long data)
msgdma_chan_desc_cleanup(mdev);
}
spin_unlock(&mdev->lock);
spin_unlock_irqrestore(&mdev->lock, flags);
}
/**