[PATCH 08/10] dmaengine: at_xdmac: Drop locking in at_xdmac_alloc_chan_resources()

From: Tudor.Ambarus
Date: Thu Jan 23 2020 - 09:03:23 EST


From: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>

There is no need for locking in device_alloc_chan_resources(),
the DMA core takes care of it by using a dma_list_mutex around
the DMA devices.

Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
---
drivers/dma/at_xdmac.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 3d6e84def7a6..8fb01bc90ba7 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1820,22 +1820,17 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *desc;
int i;
- unsigned long flags;
-
- spin_lock_irqsave(&atchan->lock, flags);

if (at_xdmac_chan_is_enabled(atchan)) {
dev_err(chan2dev(chan),
"can't allocate channel resources (channel enabled)\n");
- i = -EIO;
- goto spin_unlock;
+ return -EIO;
}

if (!list_empty(&atchan->free_descs_list)) {
dev_err(chan2dev(chan),
"can't allocate channel resources (channel not free from a previous use)\n");
- i = -EIO;
- goto spin_unlock;
+ return -EIO;
}

for (i = 0; i < init_nr_desc_per_channel; i++) {
@@ -1852,8 +1847,6 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)

dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);

-spin_unlock:
- spin_unlock_irqrestore(&atchan->lock, flags);
return i;
}

--
2.23.0