dmaengine: Cleanups for the slave <-> channel symlink support

No need to use goto to jump over the
return chan ? chan : ERR_PTR(-EPROBE_DEFER);
We can just revert the check and return right there.

Do not fail the channel request if the chan->name allocation fails, but
print a warning about it.

Change the dev_err to dev_warn if sysfs_create_link() fails as it is not
fatal.

Only attempt to remove the DMA_SLAVE_NAME symlink if it is created - or it
was attempted to be created.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200131093859.3311-2-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 3432dac..c3b1283 100644 (file)
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -756,22 +756,21 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name)
        }
        mutex_unlock(&dma_list_mutex);
 
-       if (!IS_ERR_OR_NULL(chan))
-               goto found;
-
-       return chan ? chan : ERR_PTR(-EPROBE_DEFER);
+       if (IS_ERR_OR_NULL(chan))
+               return chan ? chan : ERR_PTR(-EPROBE_DEFER);
 
 found:
-       chan->slave = dev;
        chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);
        if (!chan->name)
-               return ERR_PTR(-ENOMEM);
+               return chan;
+       chan->slave = dev;
 
        if (sysfs_create_link(&chan->dev->device.kobj, &dev->kobj,
                              DMA_SLAVE_NAME))
-               dev_err(dev, "Cannot create DMA %s symlink\n", DMA_SLAVE_NAME);
+               dev_warn(dev, "Cannot create DMA %s symlink\n", DMA_SLAVE_NAME);
        if (sysfs_create_link(&dev->kobj, &chan->dev->device.kobj, chan->name))
-               dev_err(dev, "Cannot create DMA %s symlink\n", chan->name);
+               dev_warn(dev, "Cannot create DMA %s symlink\n", chan->name);
+
        return chan;
 }
 EXPORT_SYMBOL_GPL(dma_request_chan);
@@ -830,13 +829,14 @@ void dma_release_channel(struct dma_chan *chan)
        /* drop PRIVATE cap enabled by __dma_request_channel() */
        if (--chan->device->privatecnt == 0)
                dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
+
        if (chan->slave) {
+               sysfs_remove_link(&chan->dev->device.kobj, DMA_SLAVE_NAME);
                sysfs_remove_link(&chan->slave->kobj, chan->name);
                kfree(chan->name);
                chan->name = NULL;
                chan->slave = NULL;
        }
-       sysfs_remove_link(&chan->dev->device.kobj, DMA_SLAVE_NAME);
        mutex_unlock(&dma_list_mutex);
 }
 EXPORT_SYMBOL_GPL(dma_release_channel);