dmaengine: add a release for dma class devices and dependent infrastructure

Resolves:
WARNING: at drivers/base/core.c:122 device_release+0x4d/0x52()
Device 'dma0chan0' does not have a release() function, it is broken and must be fixed.

The dma_chan_dev object is introduced to gear-match sysfs kobject and
dmaengine channel lifetimes.  When a channel is removed access to the
sysfs entries return -ENODEV until the kobject can be released.

The bulk of the change is updates to existing code to handle the extra
layer of indirection between a dma_chan and its struct device.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index c77d47c4ec5b..3603f1ea5b28 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -80,7 +80,7 @@ static bool dmatest_match_channel(struct dma_chan *chan)
 {
         if (test_channel[0] == '\0')
                 return true;
-        return strcmp(dev_name(&chan->dev), test_channel) == 0;
+        return strcmp(dma_chan_name(chan), test_channel) == 0;
 }
 
 static bool dmatest_match_device(struct dma_device *device)
@@ -325,7 +325,7 @@ static int dmatest_add_channel(struct dma_chan *chan)
 
         dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
         if (!dtc) {
-                pr_warning("dmatest: No memory for %s\n", dev_name(&chan->dev));
+                pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan));
                 return -ENOMEM;
         }
 
@@ -336,16 +336,16 @@ static int dmatest_add_channel(struct dma_chan *chan)
                 thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
                 if (!thread) {
                         pr_warning("dmatest: No memory for %s-test%u\n",
-                                   dev_name(&chan->dev), i);
+                                   dma_chan_name(chan), i);
                         break;
                 }
                 thread->chan = dtc->chan;
                 smp_wmb();
                 thread->task = kthread_run(dmatest_func, thread, "%s-test%u",
-                                dev_name(&chan->dev), i);
+                                dma_chan_name(chan), i);
                 if (IS_ERR(thread->task)) {
                         pr_warning("dmatest: Failed to run thread %s-test%u\n",
-                                        dev_name(&chan->dev), i);
+                                        dma_chan_name(chan), i);
                         kfree(thread);
                         break;
                 }
@@ -355,7 +355,7 @@ static int dmatest_add_channel(struct dma_chan *chan)
                 list_add_tail(&thread->node, &dtc->threads);
         }
 
-        pr_info("dmatest: Started %u threads using %s\n", i, dev_name(&chan->dev));
+        pr_info("dmatest: Started %u threads using %s\n", i, dma_chan_name(chan));
 
         list_add_tail(&dtc->node, &dmatest_channels);
         nr_channels++;
@@ -408,7 +408,7 @@ static void __exit dmatest_exit(void)
                 list_del(&dtc->node);
                 dmatest_cleanup_channel(dtc);
                 pr_debug("dmatest: dropped channel %s\n",
-                         dev_name(&dtc->chan->dev));
+                         dma_chan_name(dtc->chan));
                 dma_release_channel(dtc->chan);
         }
 }