| From acd40bdff4c20d4f347a1baa9df718a9fd3a0286 Mon Sep 17 00:00:00 2001 |
| From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> |
| Date: Tue, 23 May 2017 07:08:43 +0000 |
| Subject: [PATCH 087/286] rcar-dmac: fixup descriptor pointer for descriptor |
| mode |
| |
| 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> |
| (cherry picked from commit 56b177055adb246cdeca174331dbf92fc49bfccd) |
| Signed-off-by: Simon Horman <horms+renesas@verge.net.au> |
| --- |
| drivers/dma/sh/rcar-dmac.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/drivers/dma/sh/rcar-dmac.c |
| +++ b/drivers/dma/sh/rcar-dmac.c |
| @@ -1287,6 +1287,9 @@ static unsigned int rcar_dmac_chan_get_r |
| 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; |
