diff options
| -rw-r--r-- | drivers/dma/iop-adma.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c index 8acbc3ab0b9..85bfeba4d85 100644 --- a/drivers/dma/iop-adma.c +++ b/drivers/dma/iop-adma.c @@ -450,7 +450,16 @@ iop_adma_tx_submit(struct dma_async_tx_descriptor *tx) static void iop_chan_start_null_memcpy(struct iop_adma_chan *iop_chan); static void iop_chan_start_null_xor(struct iop_adma_chan *iop_chan); -/* returns the number of allocated descriptors */ +/** + * iop_adma_alloc_chan_resources - returns the number of allocated descriptors + * @chan - allocate descriptor resources for this channel + * @client - current client requesting the channel be ready for requests + * + * Note: We keep the slots for 1 operation on iop_chan->chain at all times. To + * avoid deadlock, via async_xor, num_descs_in_pool must at a minimum be + * greater than 2x the number slots needed to satisfy a device->max_xor + * request. + * */ static int iop_adma_alloc_chan_resources(struct dma_chan *chan, struct dma_client *client) { |