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dmaengine: advertise all channels on a device to dma_filter_fn

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Allow dma_filter_fn routines to disambiguate multiple channels on a device
rather than assuming that all channels on a device are equal.

Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Reported-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2009-01-06 11:38:21 -07:00
parent 864498aaa9
commit e2346677af
1 changed files with 13 additions and 20 deletions
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33
drivers/dma/dmaengine.c
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@ -454,10 +454,10 @@ static void dma_channel_rebalance(void)
} }
} }
static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev) static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev,
dma_filter_fn fn, void *fn_param)
{ {
struct dma_chan *chan; struct dma_chan *chan;
struct dma_chan *ret = NULL;
if (!__dma_device_satisfies_mask(dev, mask)) { if (!__dma_device_satisfies_mask(dev, mask)) {
pr_debug("%s: wrong capabilities\n", __func__); pr_debug("%s: wrong capabilities\n", __func__);
@ -479,11 +479,15 @@ static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_devic
__func__, dma_chan_name(chan)); __func__, dma_chan_name(chan));
continue; continue;
} }
ret = chan; if (fn && !fn(chan, fn_param)) {
break; pr_debug("%s: %s filter said false\n",
__func__, dma_chan_name(chan));
continue;
}
return chan;
} }
return ret; return NULL;
} }
/** /**
@ -496,22 +500,13 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v
{ {
struct dma_device *device, *_d; struct dma_device *device, *_d;
struct dma_chan *chan = NULL; struct dma_chan *chan = NULL;
bool ack;
int err; int err;
/* Find a channel */ /* Find a channel */
mutex_lock(&dma_list_mutex); mutex_lock(&dma_list_mutex);
list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
chan = private_candidate(mask, device); chan = private_candidate(mask, device, fn, fn_param);
if (!chan) if (chan) {
continue;
if (fn)
ack = fn(chan, fn_param);
else
ack = true;
if (ack) {
/* Found a suitable channel, try to grab, prep, and /* Found a suitable channel, try to grab, prep, and
* return it. We first set DMA_PRIVATE to disable * return it. We first set DMA_PRIVATE to disable
* balance_ref_count as this channel will not be * balance_ref_count as this channel will not be
@ -529,10 +524,8 @@ 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;
} else chan = NULL;
pr_debug("%s: %s filter said false\n", }
__func__, dma_chan_name(chan));
chan = NULL;
} }
mutex_unlock(&dma_list_mutex); mutex_unlock(&dma_list_mutex);