dmaengine: xilinx: xdma: Add error checking in xdma_channel_isr()

Check and clear the status register value before proceeding any
further in xdma_channel_isr(). It is necessary to do it since the
interrupt may occur on any error condition enabled at the start of a
transfer.

Signed-off-by: Jan Kuliga <jankul@alatek.krakow.pl>
Link: https://lore.kernel.org/r/20231218113943.9099-6-jankul@alatek.krakow.pl
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c
index 0c73508638738c8765cc340c986b213412025c5d..9a1d2939a333f7230b0e533620df7e73510ded5f 100644 (file)
--- a/drivers/dma/xilinx/xdma.c
+++ b/drivers/dma/xilinx/xdma.c
@@ -811,6 +811,18 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
        desc = to_xdma_desc(vd);
        xdev = xchan->xdev_hdl;
 
+       /* Clear-on-read the status register */
+       ret = regmap_read(xdev->rmap, xchan->base + XDMA_CHAN_STATUS_RC, &st);
+       if (ret)
+               goto out;
+
+       st &= XDMA_CHAN_STATUS_MASK;
+       if ((st & XDMA_CHAN_ERROR_MASK) ||
+           !(st & (CHAN_CTRL_IE_DESC_COMPLETED | CHAN_CTRL_IE_DESC_STOPPED))) {
+               xdma_err(xdev, "channel error, status register value: 0x%x", st);
+               goto out;
+       }
+
        ret = regmap_read(xdev->rmap, xchan->base + XDMA_CHAN_COMPLETED_DESC,
                          &complete_desc_num);
        if (ret)
@@ -818,14 +830,6 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 
        if (desc->cyclic) {
                desc->completed_desc_num = complete_desc_num;
-
-               ret = regmap_read(xdev->rmap, xchan->base + XDMA_CHAN_STATUS,
-                                 &st);
-               if (ret)
-                       goto out;
-
-               regmap_write(xdev->rmap, xchan->base + XDMA_CHAN_STATUS, st);
-
                vchan_cyclic_callback(vd);
        } else {
                xchan->busy = false;