redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

iop_adma: document how to calculate the minimum descriptor pool size 

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
hifive-unleashed-5.1
Dan Williams 2008-07-17 17:59:56 -07:00
parent c7141d005a
commit 5eb907aaaf
1 changed files with 10 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/dma/iop-adma.c
View File

@ -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)
{