]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commitdiff
rcar-dmac: fixup descriptor pointer for descriptor mode
authorKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tue, 23 May 2017 07:08:43 +0000 (07:08 +0000)
committerVinod Koul <vinod.koul@intel.com>
Tue, 30 May 2017 06:19:28 +0000 (11:49 +0530)
In descriptor mode, the descriptor running pointer is not maintained
by the interrupt handler, thus, driver finds the running descriptor
from the descriptor pointer field in the CHCRB register.
But, CHCRB::DPTR indicates *next* descriptor pointer, not current.
Thus, The residue calculation will be missed. This patch fixup it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
drivers/dma/sh/rcar-dmac.c

index db41795fe42ae6ed355de41f12b5c90ea661bde4..bd261c9e9664b6ac951939641091bc0bb7466380 100644 (file)
@@ -1287,6 +1287,9 @@ static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan,
        if (desc->hwdescs.use) {
                dptr = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) &
                        RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT;
+               if (dptr == 0)
+                       dptr = desc->nchunks;
+               dptr--;
                WARN_ON(dptr >= desc->nchunks);
        } else {
                running = desc->running;