From 855c2e1d1842f0101a051378094548ca581d7a7d Mon Sep 17 00:00:00 2001 From: Jan Kuliga Date: Mon, 18 Dec 2023 12:39:39 +0100 Subject: dmaengine: xilinx: xdma: Rework xdma_terminate_all() Simplify xdma_xfer_stop(). Stop the dma engine and clear its status register unconditionally - just do what its name states. This change also allows to call it without grabbing a lock, which minimizes the total time spent with a spinlock held. Delete the currently processed vd.node from the vc.desc_issued list prior to passing it to vchan_terminate_vdesc(). In case there's more than one descriptor pending on vc.desc_issued list, calling vchan_terminate_desc() results in losing the link between vc.desc_issued list head and the second descriptor on the list. Doing so results in resources leakege, as vchan_dma_desc_free_list() won't be able to properly free memory resources attached to descriptors, resulting in dma_pool_destroy() failure. Don't call vchan_dma_desc_free_list() from within xdma_terminate_all(). Move all terminated descriptors to the vc.desc_terminated list instead. This allows to postpone freeing memory resources associated with descriptors until the call to vchan_synchronize(), which is called from xdma_synchronize() callback. This is the right way to do it - xdma_terminate_all() should return as soon as possible, while freeing resources (that may be time consuming in case of large number of descriptors) can be done safely later. Fixes: f5c392d106e7 ("dmaengine: xilinx: xdma: Add terminate_all/synchronize callbacks") Signed-off-by: Jan Kuliga Link: https://lore.kernel.org/r/20231218113943.9099-5-jankul@alatek.krakow.pl Signed-off-by: Vinod Koul --- drivers/dma/xilinx/xdma.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'drivers/dma') diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c index c22701e76b69..0c7350863873 100644 --- a/drivers/dma/xilinx/xdma.c +++ b/drivers/dma/xilinx/xdma.c @@ -379,12 +379,9 @@ static int xdma_xfer_start(struct xdma_chan *xchan) */ static int xdma_xfer_stop(struct xdma_chan *xchan) { - struct virt_dma_desc *vd = vchan_next_desc(&xchan->vchan); - struct xdma_device *xdev = xchan->xdev_hdl; int ret; - - if (!vd || !xchan->busy) - return -EINVAL; + u32 val; + struct xdma_device *xdev = xchan->xdev_hdl; /* clear run stop bit to prevent any further auto-triggering */ ret = regmap_write(xdev->rmap, xchan->base + XDMA_CHAN_CONTROL_W1C, @@ -392,7 +389,10 @@ static int xdma_xfer_stop(struct xdma_chan *xchan) if (ret) return ret; - xchan->busy = false; + /* Clear the channel status register */ + ret = regmap_read(xdev->rmap, xchan->base + XDMA_CHAN_STATUS_RC, &val); + if (ret) + return ret; return 0; } @@ -505,25 +505,25 @@ static void xdma_issue_pending(struct dma_chan *chan) static int xdma_terminate_all(struct dma_chan *chan) { struct xdma_chan *xdma_chan = to_xdma_chan(chan); - struct xdma_desc *desc = NULL; struct virt_dma_desc *vd; unsigned long flags; LIST_HEAD(head); - spin_lock_irqsave(&xdma_chan->vchan.lock, flags); xdma_xfer_stop(xdma_chan); + spin_lock_irqsave(&xdma_chan->vchan.lock, flags); + + xdma_chan->busy = false; vd = vchan_next_desc(&xdma_chan->vchan); - if (vd) - desc = to_xdma_desc(vd); - if (desc) { - dma_cookie_complete(&desc->vdesc.tx); - vchan_terminate_vdesc(&desc->vdesc); + if (vd) { + list_del(&vd->node); + dma_cookie_complete(&vd->tx); + vchan_terminate_vdesc(vd); } - vchan_get_all_descriptors(&xdma_chan->vchan, &head); + list_splice_tail(&head, &xdma_chan->vchan.desc_terminated); + spin_unlock_irqrestore(&xdma_chan->vchan.lock, flags); - vchan_dma_desc_free_list(&xdma_chan->vchan, &head); return 0; } -- cgit v1.2.3