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| author |   Christophe JAILLET <christophe.jaillet@wanadoo.fr> | 2022-02-06 10:47:45 +0100 |
|---|---|---|
| committer |   Vinod Koul <vkoul@kernel.org> | 2022-04-11 19:52:40 +0530 |
| commit | 52126d4c03798cc55aa927fea4c776ab26b5a5f0 (patch) | |
| tree | c438badcf0ee9f80478bf7963db70f14d7c8d197 | |
| parent | dmaengine: idxd: update IAA definitions for user header (diff) | |
| download | linux-dev-52126d4c03798cc55aa927fea4c776ab26b5a5f0.tar.xz linux-dev-52126d4c03798cc55aa927fea4c776ab26b5a5f0.zip | |
dmaengine: Remove a useless mutex
According to lib/idr.c,
The IDA handles its own locking. It is safe to call any of the IDA
functions without synchronisation in your code.
so the 'chan_mutex' mutex can just be removed.
It is here only to protect some ida_alloc()/ida_free() calls.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/7180452c1d77b039e27b6f9418e0e7d9dd33c431.1644140845.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>
| -rw-r--r-- | drivers/dma/dmaengine.c | 7 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 1 |
2 files changed, 0 insertions, 8 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 2cfa8458b51b..e80feeea0e01 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -1053,9 +1053,7 @@ static int __dma_async_device_channel_register(struct dma_device *device, * When the chan_id is a negative value, we are dynamically adding * the channel. Otherwise we are static enumerating. */ - mutex_lock(&device->chan_mutex); chan->chan_id = ida_alloc(&device->chan_ida, GFP_KERNEL); - mutex_unlock(&device->chan_mutex); if (chan->chan_id < 0) { pr_err("%s: unable to alloc ida for chan: %d\n", __func__, chan->chan_id); @@ -1078,9 +1076,7 @@ static int __dma_async_device_channel_register(struct dma_device *device, return 0; err_out_ida: - mutex_lock(&device->chan_mutex); ida_free(&device->chan_ida, chan->chan_id); - mutex_unlock(&device->chan_mutex); err_free_dev: kfree(chan->dev); err_free_local: @@ -1113,9 +1109,7 @@ static void __dma_async_device_channel_unregister(struct dma_device *device, device->chancnt--; chan->dev->chan = NULL; mutex_unlock(&dma_list_mutex); - mutex_lock(&device->chan_mutex); ida_free(&device->chan_ida, chan->chan_id); - mutex_unlock(&device->chan_mutex); device_unregister(&chan->dev->device); free_percpu(chan->local); } @@ -1250,7 +1244,6 @@ int dma_async_device_register(struct dma_device *device) if (rc != 0) return rc; - mutex_init(&device->chan_mutex); ida_init(&device->chan_ida); /* represent channels in sysfs. Probably want devs too */ diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 842d4f7ca752..6db9e03afd0b 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -870,7 +870,6 @@ struct dma_device { struct device *dev; struct module *owner; struct ida chan_ida; - struct mutex chan_mutex; /* to protect chan_ida */ u32 src_addr_widths; u32 dst_addr_widths; |