From: Laurent Pinchart <[email protected]> Cookies corresponding to pending transfers have a residue value equal to the full size of the corresponding descriptor. The driver miscomputes that and uses the size of the active descriptor instead. Fix it.
Reported-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Laurent Pinchart <[email protected]> [geert: Also check desc.active list] Signed-off-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Niklas Söderlund <[email protected]> --- drivers/dma/sh/rcar-dmac.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 59951fb..86aef28 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -1145,19 +1145,47 @@ static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan, struct rcar_dmac_desc *desc = chan->desc.running; struct rcar_dmac_xfer_chunk *running = NULL; struct rcar_dmac_xfer_chunk *chunk; + enum dma_status status; unsigned int residue = 0; unsigned int dptr = 0; if (!desc) return 0; + + /* + * If the cookie corresponds to a descriptor that has been completed + * there is no residue. The same check has already been performed by the + * caller but without holding the channel lock, so the descriptor could + * now be complete. + */ + status = dma_cookie_status(&chan->chan, cookie, NULL); + if (status == DMA_COMPLETE) + return 0; + /* * If the cookie doesn't correspond to the currently running transfer * then the descriptor hasn't been processed yet, and the residue is * equal to the full descriptor size. */ - if (cookie != desc->async_tx.cookie) - return desc->size; + if (cookie != desc->async_tx.cookie) { + list_for_each_entry(desc, &chan->desc.pending, node) { + if (cookie == desc->async_tx.cookie) + return desc->size; + } + list_for_each_entry(desc, &chan->desc.active, node) { + if (cookie == desc->async_tx.cookie) + return desc->size; + } + + /* + * No descriptor found for the cookie, there's thus no residue. + * This shouldn't happen if the calling driver passes a correct + * cookie value. + */ + WARN(1, "No descriptor for cookie!"); + return 0; + } /* * In descriptor mode the descriptor running pointer is not maintained -- 2.8.3
