Messages in this thread Patch in this message | | | From | Jamie Iles <> | Subject | [PATCH repost 1/4] dmaengine/dw_dmac: don't scan descriptors if no xfers in progress | Date | Fri, 21 Jan 2011 14:11:52 +0000 |
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Some hardware (picoChip picoXCell in particular) sometimes has the block transfer complete bit being set for a channel after the whole transfer has completed. If we don't have any transfers in the active list then don't bother to scan the descriptors. This often happens in normal operation and doesn't require the channel to be reset.
v2: cleanup whitespace
Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jamie Iles <jamie.iles@picochip.com> --- drivers/dma/dw_dmac.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index a3991ab..db22754 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -291,6 +291,9 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc) return; } + if (list_empty(&dwc->active_list)) + return; + dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp); list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) { -- 1.7.3.4
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