Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0f571515 authored by Atsushi Nemoto's avatar Atsushi Nemoto Committed by Dan Williams
Browse files

dmaengine: Add privatecnt to revert DMA_PRIVATE property 



Currently dma_request_channel() set DMA_PRIVATE capability but never
clear it.  So if a public channel was once grabbed by
dma_request_channel(), the device stay PRIVATE forever.  Add
privatecnt member to dma_device to correctly revert it.

[lg@denx.de: fix bad usage of 'chan' in dma_async_device_register]
Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: default avatarMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent e44e0aa3

drivers/dma/dmaengine.c

+8 −0
Original line number Original line Diff line number Diff line
@@ -507,6 +507,7 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v 
			 * published in the general-purpose allocator

			 * published in the general-purpose allocator

			 */

			 */

			dma_cap_set(DMA_PRIVATE, device->cap_mask);

			dma_cap_set(DMA_PRIVATE, device->cap_mask);

			device->privatecnt++;

			err = dma_chan_get(chan);

			err = dma_chan_get(chan);





			if (err == -ENODEV) {

			if (err == -ENODEV) {
@@ -518,6 +519,8 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v 
				       dma_chan_name(chan), err);

				       dma_chan_name(chan), err);

			else

			else

				break;

				break;

			if (--device->privatecnt == 0)

				dma_cap_clear(DMA_PRIVATE, device->cap_mask);

			chan->private = NULL;

			chan->private = NULL;

			chan = NULL;

			chan = NULL;

		}

		}
@@ -537,6 +540,9 @@ void dma_release_channel(struct dma_chan *chan) 
	WARN_ONCE(chan->client_count != 1,

	WARN_ONCE(chan->client_count != 1,

		  "chan reference count %d != 1\n", chan->client_count);

		  "chan reference count %d != 1\n", chan->client_count);

	dma_chan_put(chan);

	dma_chan_put(chan);

	/* drop PRIVATE cap enabled by __dma_request_channel() */

	if (--chan->device->privatecnt == 0)

		dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);

	chan->private = NULL;

	chan->private = NULL;

	mutex_unlock(&dma_list_mutex);

	mutex_unlock(&dma_list_mutex);

}

}
@@ -719,6 +725,8 @@ int dma_async_device_register(struct dma_device *device) 
			}

			}

		}

		}

	list_add_tail_rcu(&device->global_node, &dma_device_list);

	list_add_tail_rcu(&device->global_node, &dma_device_list);

	if (dma_has_cap(DMA_PRIVATE, device->cap_mask))

		device->privatecnt++;	/* Always private */

	dma_channel_rebalance();

	dma_channel_rebalance();

	mutex_unlock(&dma_list_mutex);

	mutex_unlock(&dma_list_mutex);

include/linux/dmaengine.h

+9 −0
Original line number Original line Diff line number Diff line
@@ -202,6 +202,7 @@ struct dma_async_tx_descriptor { 
/**

/**

 * struct dma_device - info on the entity supplying DMA services

 * struct dma_device - info on the entity supplying DMA services

 * @chancnt: how many DMA channels are supported

 * @chancnt: how many DMA channels are supported

 * @privatecnt: how many DMA channels are requested by dma_request_channel

 * @channels: the list of struct dma_chan

 * @channels: the list of struct dma_chan

 * @global_node: list_head for global dma_device_list

 * @global_node: list_head for global dma_device_list

 * @cap_mask: one or more dma_capability flags

 * @cap_mask: one or more dma_capability flags
@@ -224,6 +225,7 @@ struct dma_async_tx_descriptor { 
struct dma_device {

struct dma_device {





	unsigned int chancnt;

	unsigned int chancnt;

	unsigned int privatecnt;

	struct list_head channels;

	struct list_head channels;

	struct list_head global_node;

	struct list_head global_node;

	dma_cap_mask_t  cap_mask;

	dma_cap_mask_t  cap_mask;
@@ -352,6 +354,13 @@ __dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp) 
	set_bit(tx_type, dstp->bits);

	set_bit(tx_type, dstp->bits);

}

}





#define dma_cap_clear(tx, mask) __dma_cap_clear((tx), &(mask))

static inline void

__dma_cap_clear(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)

{

	clear_bit(tx_type, dstp->bits);

}



#define dma_cap_zero(mask) __dma_cap_zero(&(mask))

#define dma_cap_zero(mask) __dma_cap_zero(&(mask))

static inline void __dma_cap_zero(dma_cap_mask_t *dstp)

static inline void __dma_cap_zero(dma_cap_mask_t *dstp)

{

{