Messages in this thread | | | Date | Fri, 3 Dec 2010 15:20:01 -0800 | Subject | Re: [PATCH 1/4] dmaengine/dw_dmac: don't scan descriptors if no xfers in progress | From | Dan Williams <> |
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[ copying Haavard's new address ]
On Tue, Nov 23, 2010 at 3:06 AM, Jamie Iles <jamie@jamieiles.com> wrote: > 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. > > Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> > 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..08c51d4 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) { > -- > 1.7.2.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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