dmaengine: dw: platform: power on device on shutdown

BugLink: http://bugs.launchpad.net/bugs/1602579

We have to call dw_dma_disable() to stop any ongoing transfer. On some
platforms we can't do that since DMA device is powered off. Moreover we have no
possibility at that point to check if the platform is affected or not. That's
why we call pm_runtime_get_sync() / pm_runtime_put() unconditionally. On the
other hand we can't use pm_runtime_suspended() because runtime PM framework is
not fully used by the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 32146588)
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/dma/dw/platform.c

@@ -239,7 +239,19 @@ static void dw_shutdown(struct platform_device *pdev)
 {
 	struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 
+	/*
+	 * We have to call dw_dma_disable() to stop any ongoing transfer. On
+	 * some platforms we can't do that since DMA device is powered off.
+	 * Moreover we have no possibility to check if the platform is affected
+	 * or not. That's why we call pm_runtime_get_sync() / pm_runtime_put()
+	 * unconditionally. On the other hand we can't use
+	 * pm_runtime_suspended() because runtime PM framework is not fully
+	 * used by the driver.
+	 */
+	pm_runtime_get_sync(chip->dev);
 	dw_dma_disable(chip);
+	pm_runtime_put_sync_suspend(chip->dev);
+
 	clk_disable_unprepare(chip->clk);
 }