dmaengine: at_xdma: handle errors of at_xdmac_alloc_desc() correctly

It seems that it is valid to have less than the requested number of
descriptors. But what is not valid and leads to subsequent errors is to
have zero descriptors. In that case, abort the probing.

Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20220526135111.1470926-1-michael@walle.cc
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 3e9d726504e2ed776ddc1155ef43130da5811533..7b3e6030f7b4b007e0ace835bbaeccbda21cb8d3 100644 (file)
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1900,6 +1900,11 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
        for (i = 0; i < init_nr_desc_per_channel; i++) {
                desc = at_xdmac_alloc_desc(chan, GFP_KERNEL);
                if (!desc) {
+                       if (i == 0) {
+                               dev_warn(chan2dev(chan),
+                                        "can't allocate any descriptors\n");
+                               return -EIO;
+                       }
                        dev_warn(chan2dev(chan),
                                "only %d descriptors have been allocated\n", i);
                        break;