4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Ujfalusi <peter.ujfal...@ti.com>

commit 23f49fd2ea9bc8e1c8cff0126cd71b071ea9e91f upstream.

The dynamic or on demand pm_runtime does not work correctly on am335x and
am437x due to interference with hwmod.
Fall back using the pm_runtime usage as it was in the old driver stack,
meaning that at probe time call pm_runtime_enable() and
pm_runtime_get_sync() for the TPTCs as well.

Fixes: 1be5336bc7ba ("dmaengine: edma: New device tree binding")

Signed-off-by: Peter Ujfalusi <peter.ujfal...@ti.com>
Reported-by: Tero Kristo <t-kri...@ti.com>
Signed-off-by: Vinod Koul <vinod.k...@intel.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/dma/edma.c |   38 +++-----------------------------------
 1 file changed, 3 insertions(+), 35 deletions(-)

--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -1563,32 +1563,6 @@ static irqreturn_t dma_ccerr_handler(int
        return IRQ_HANDLED;
 }
 
-static void edma_tc_set_pm_state(struct edma_tc *tc, bool enable)
-{
-       struct platform_device *tc_pdev;
-       int ret;
-
-       if (!IS_ENABLED(CONFIG_OF) || !tc)
-               return;
-
-       tc_pdev = of_find_device_by_node(tc->node);
-       if (!tc_pdev) {
-               pr_err("%s: TPTC device is not found\n", __func__);
-               return;
-       }
-       if (!pm_runtime_enabled(&tc_pdev->dev))
-               pm_runtime_enable(&tc_pdev->dev);
-
-       if (enable)
-               ret = pm_runtime_get_sync(&tc_pdev->dev);
-       else
-               ret = pm_runtime_put_sync(&tc_pdev->dev);
-
-       if (ret < 0)
-               pr_err("%s: pm_runtime_%s_sync() failed for %s\n", __func__,
-                      enable ? "get" : "put", dev_name(&tc_pdev->dev));
-}
-
 /* Alloc channel resources */
 static int edma_alloc_chan_resources(struct dma_chan *chan)
 {
@@ -1625,8 +1599,6 @@ static int edma_alloc_chan_resources(str
                EDMA_CHAN_SLOT(echan->ch_num), chan->chan_id,
                echan->hw_triggered ? "HW" : "SW");
 
-       edma_tc_set_pm_state(echan->tc, true);
-
        return 0;
 
 err_slot:
@@ -1663,7 +1635,6 @@ static void edma_free_chan_resources(str
                echan->alloced = false;
        }
 
-       edma_tc_set_pm_state(echan->tc, false);
        echan->tc = NULL;
        echan->hw_triggered = false;
 
@@ -2408,10 +2379,8 @@ static int edma_pm_suspend(struct device
        int i;
 
        for (i = 0; i < ecc->num_channels; i++) {
-               if (echan[i].alloced) {
+               if (echan[i].alloced)
                        edma_setup_interrupt(&echan[i], false);
-                       edma_tc_set_pm_state(echan[i].tc, false);
-               }
        }
 
        return 0;
@@ -2441,8 +2410,6 @@ static int edma_pm_resume(struct device
 
                        /* Set up channel -> slot mapping for the entry slot */
                        edma_set_chmap(&echan[i], echan[i].slot[0]);
-
-                       edma_tc_set_pm_state(echan[i].tc, true);
                }
        }
 
@@ -2466,7 +2433,8 @@ static struct platform_driver edma_drive
 
 static int edma_tptc_probe(struct platform_device *pdev)
 {
-       return 0;
+       pm_runtime_enable(&pdev->dev);
+       return pm_runtime_get_sync(&pdev->dev);
 }
 
 static struct platform_driver edma_tptc_driver = {


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