Messages in this thread | | | From | Måns Rullgård <> | Subject | Re: [PATCH] dmaengine: dw: fix cyclic transfers | Date | Mon, 11 Jan 2016 12:19:50 +0000 |
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Viresh Kumar <viresh.kumar@linaro.org> writes:
> On 10-01-16, 20:54, Mans Rullgard wrote: >> Commit 61e183f83069 ("dmaengine/dw_dmac: Reconfigure interrupt and >> chan_cfg register on resume") moved some channel initialisation to >> a new function which must be called before starting a transfer. >> >> This adds the necessary dwc_initialize() call to dw_dma_cyclic_start() >> which was missed in the original commit. >> >> Fixes: 61e183f83069 ("dmaengine/dw_dmac: Reconfigure interrupt and chan_cfg register on resume") >> Signed-off-by: Mans Rullgard <mans@mansr.com> >> --- >> Andy, do you want to collect this with your other patches? It's trivial >> enough that it can go in separately without conflicts too. >> --- >> drivers/dma/dw/core.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c >> index 7067b6ddc1db..2917f75b67b4 100644 >> --- a/drivers/dma/dw/core.c >> +++ b/drivers/dma/dw/core.c >> @@ -1265,6 +1265,8 @@ int dw_dma_cyclic_start(struct dma_chan *chan) >> return -EBUSY; >> } >> >> + dwc_initialize(dwc); >> + >> dma_writel(dw, CLEAR.ERROR, dwc->mask); >> dma_writel(dw, CLEAR.XFER, dwc->mask); > > Ahh, that's a very very old bug :(
It's not the only one, I'm afraid.
> Okay, things got cleaned up by putting the dwc_initialize() call > within dwc_dostart() and so it worked for all other DMA APIs. > > What about calling dwc_dostart() from within dw_dma_cyclic_start()? > That will simplify it and remove code duplication issue as well.
Good idea. New patch coming up.
-- Måns Rullgård
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