Commit 84adccfb authored Mar 24, 2011 by Viresh Kumar Committed by Vinod Koul Mar 31, 2011

dmaengine/dw_dmac fix: dwc_scan_descriptors must compare first desc address also with llp

dwc_scan_descriptors scans all descriptors from active_list in case transfer is
not completed. It compares first_desc->lli.llp, and then all childrens of its
tx_list. But it doesn't compare its own address, i.e. first_desc->txd.phys, as
this is what we have initially programmed into the controller register. So this
causes dma to stop and finish a transfer, which was never started. And thus
fail.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

parent 3ea205c4

drivers/dma/dw_dmac.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -304,6 +304,11 @@ static void dwc_scan_descriptors(struct dw_dma dw, struct dw_dma_chan dwc)
		dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);

		list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
		/* check first descriptors addr */
		if (desc->txd.phys == llp)
		return;

		/* check first descriptors llp */
		if (desc->lli.llp == llp)
		/* This one is currently in progress */
		return;