diff options
Diffstat (limited to 'drivers/dma/dmaengine.c')
| -rw-r--r-- | drivers/dma/dmaengine.c | 53 |
1 files changed, 45 insertions, 8 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 08ba8473a284..272bed6c8ba7 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -500,12 +500,8 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) caps->max_burst = device->max_burst; caps->residue_granularity = device->residue_granularity; caps->descriptor_reuse = device->descriptor_reuse; - - /* - * Some devices implement only pause (e.g. to get residuum) but no - * resume. However cmd_pause is advertised as pause AND resume. - */ - caps->cmd_pause = !!(device->device_pause && device->device_resume); + caps->cmd_pause = !!device->device_pause; + caps->cmd_resume = !!device->device_resume; caps->cmd_terminate = !!device->device_terminate_all; return 0; @@ -774,8 +770,14 @@ struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask) return ERR_PTR(-ENODEV); chan = __dma_request_channel(mask, NULL, NULL); - if (!chan) - chan = ERR_PTR(-ENODEV); + if (!chan) { + mutex_lock(&dma_list_mutex); + if (list_empty(&dma_device_list)) + chan = ERR_PTR(-EPROBE_DEFER); + else + chan = ERR_PTR(-ENODEV); + mutex_unlock(&dma_list_mutex); + } return chan; } @@ -1139,6 +1141,41 @@ void dma_async_device_unregister(struct dma_device *device) } EXPORT_SYMBOL(dma_async_device_unregister); +static void dmam_device_release(struct device *dev, void *res) +{ + struct dma_device *device; + + device = *(struct dma_device **)res; + dma_async_device_unregister(device); +} + +/** + * dmaenginem_async_device_register - registers DMA devices found + * @device: &dma_device + * + * The operation is managed and will be undone on driver detach. + */ +int dmaenginem_async_device_register(struct dma_device *device) +{ + void *p; + int ret; + + p = devres_alloc(dmam_device_release, sizeof(void *), GFP_KERNEL); + if (!p) + return -ENOMEM; + + ret = dma_async_device_register(device); + if (!ret) { + *(struct dma_device **)p = device; + devres_add(device->dev, p); + } else { + devres_free(p); + } + + return ret; +} +EXPORT_SYMBOL(dmaenginem_async_device_register); + struct dmaengine_unmap_pool { struct kmem_cache *cache; const char *name; |