[PATCH v2 1/2] dmaengine: Cleanups for the slave <-> channel symlink support

From: Peter Ujfalusi
Date: Fri Jan 31 2020 - 04:38:27 EST


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@xxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/dma/dmaengine.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 7b1cefc3213a..342d23132fca 100644
--- 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);
--
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki