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authorAlexandre Bounine <alexandre.bounine@idt.com>2016-03-22 14:26:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-22 15:36:02 -0700
commit83472457505c454592d91807754135d0ad34b125 (patch)
tree3c93685eba4fff5416df6201fdd6f9b4c2fc7774
parent72d8a0d23083ba89fb00a7ad9b07419e34ebe47c (diff)
downloadlinux-83472457505c454592d91807754135d0ad34b125.tar.bz2
rapidio/tsi721_dma: update error reporting from prep_sg callback
Switch to returning error-valued pointer instead of simple NULL pointer. This allows to properly identify situation when request queue is full and therefore gives to upper layer an option to retry operation later. Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/rapidio/devices/tsi721_dma.c37
1 files changed, 21 insertions, 16 deletions
diff --git a/drivers/rapidio/devices/tsi721_dma.c b/drivers/rapidio/devices/tsi721_dma.c
index 494482e4ab0a..5bc9071ebcae 100644
--- a/drivers/rapidio/devices/tsi721_dma.c
+++ b/drivers/rapidio/devices/tsi721_dma.c
@@ -767,7 +767,7 @@ struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
void *tinfo)
{
struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
- struct tsi721_tx_desc *desc, *_d;
+ struct tsi721_tx_desc *desc;
struct rio_dma_ext *rext = tinfo;
enum dma_rtype rtype;
struct dma_async_tx_descriptor *txd = NULL;
@@ -775,7 +775,7 @@ struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
if (!sgl || !sg_len) {
tsi_err(&dchan->dev->device, "DMAC%d No SG list",
bdma_chan->id);
- return NULL;
+ return ERR_PTR(-EINVAL);
}
tsi_debug(DMA, &dchan->dev->device, "DMAC%d %s", bdma_chan->id,
@@ -800,28 +800,33 @@ struct dma_async_tx_descriptor *tsi721_prep_rio_sg(struct dma_chan *dchan,
tsi_err(&dchan->dev->device,
"DMAC%d Unsupported DMA direction option",
bdma_chan->id);
- return NULL;
+ return ERR_PTR(-EINVAL);
}
spin_lock_bh(&bdma_chan->lock);
- list_for_each_entry_safe(desc, _d, &bdma_chan->free_list, desc_node) {
- if (async_tx_test_ack(&desc->txd)) {
- list_del_init(&desc->desc_node);
- desc->destid = rext->destid;
- desc->rio_addr = rext->rio_addr;
- desc->rio_addr_u = 0;
- desc->rtype = rtype;
- desc->sg_len = sg_len;
- desc->sg = sgl;
- txd = &desc->txd;
- txd->flags = flags;
- break;
- }
+ if (!list_empty(&bdma_chan->free_list)) {
+ desc = list_first_entry(&bdma_chan->free_list,
+ struct tsi721_tx_desc, desc_node);
+ list_del_init(&desc->desc_node);
+ desc->destid = rext->destid;
+ desc->rio_addr = rext->rio_addr;
+ desc->rio_addr_u = 0;
+ desc->rtype = rtype;
+ desc->sg_len = sg_len;
+ desc->sg = sgl;
+ txd = &desc->txd;
+ txd->flags = flags;
}
spin_unlock_bh(&bdma_chan->lock);
+ if (!txd) {
+ tsi_debug(DMA, &dchan->dev->device,
+ "DMAC%d free TXD is not available", bdma_chan->id);
+ return ERR_PTR(-EBUSY);
+ }
+
return txd;
}