From 83472457505c454592d91807754135d0ad34b125 Mon Sep 17 00:00:00 2001 From: Alexandre Bounine Date: Tue, 22 Mar 2016 14:26:59 -0700 Subject: [PATCH] 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 Cc: Matt Porter Cc: Aurelien Jacquiot Cc: Andre van Herk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rapidio/devices/tsi721_dma.c | 37 ++++++++++++++++------------ 1 file 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; } -- 2.20.1