dmaengine: rcar-dmac: Fix residue reporting for pending descriptors

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 <geert@linux-m68k.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
[geert: Also check desc.active list]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
(cherry picked from commit 55bd582b4d8c2266bc43cbae2ddfce31b489618f)
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
1 file changed