dmaengine: advertise all channels on a device to dma_filter_fn
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>
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index dd43410..9d3594c 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -454,10 +454,10 @@
}
}
-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 *ret = NULL;
if (!__dma_device_satisfies_mask(dev, mask)) {
pr_debug("%s: wrong capabilities\n", __func__);
@@ -479,11 +479,15 @@
__func__, dma_chan_name(chan));
continue;
}
- ret = chan;
- break;
+ if (fn && !fn(chan, fn_param)) {
+ 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_device *device, *_d;
struct dma_chan *chan = NULL;
- bool ack;
int err;
/* Find a channel */
mutex_lock(&dma_list_mutex);
list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
- chan = private_candidate(mask, device);
- if (!chan)
- continue;
-
- if (fn)
- ack = fn(chan, fn_param);
- else
- ack = true;
-
- if (ack) {
+ chan = private_candidate(mask, device, fn, fn_param);
+ if (chan) {
/* Found a suitable channel, try to grab, prep, and
* return it. We first set DMA_PRIVATE to disable
* balance_ref_count as this channel will not be
@@ -529,10 +524,8 @@
dma_chan_name(chan), err);
else
break;
- } else
- pr_debug("%s: %s filter said false\n",
- __func__, dma_chan_name(chan));
- chan = NULL;
+ chan = NULL;
+ }
}
mutex_unlock(&dma_list_mutex);