Commit b6d1778b authored Feb 26, 2015 by Geert Uytterhoeven Committed by Vinod Koul Mar 02, 2015

dmaengine: shdma: Move DMA stop to (runtime) suspend callbacks



During system reboot, the sh-dma-engine device may be runtime-suspended,
causing a crash:

    Unhandled fault: imprecise external abort (0x1406) at 0x0002c02c
    Internal error: : 1406 [#1] SMP ARM
    ...
    PC is at sh_dmae_ctl_stop+0x28/0x64
    LR is at sh_dmae_ctl_stop+0x24/0x64

If the sh-dma-engine is runtime-suspended, its module clock is turned
off, and its registers cannot be accessed.

To fix this, move the call to sh_dmae_ctl_stop(), which touches the
DMAOR register, to the sh_dmae_suspend() and sh_dmae_runtime_suspend()
callbacks.  This makes PM operations more symmetric, as both
sh_dmae_resume() and sh_dmae_runtime_resume() already call sh_dmae_rst()
to re-initialize the DMAOR register.

Remove sh_dmae_shutdown(), as it became empty.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

parent 3a314f14

drivers/dma/sh/shdmac.c

+7 −8

Original line number	Diff line number	Diff line
		@@ -582,15 +582,12 @@ static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
		}
		}

		static void sh_dmae_shutdown(struct platform_device *pdev)
		{
		struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
		sh_dmae_ctl_stop(shdev);
		}

		#ifdef CONFIG_PM
		static int sh_dmae_runtime_suspend(struct device *dev)
		{
		struct sh_dmae_device *shdev = dev_get_drvdata(dev);

		sh_dmae_ctl_stop(shdev);
		return 0;
		}

		@@ -605,6 +602,9 @@ static int sh_dmae_runtime_resume(struct device *dev)
		#ifdef CONFIG_PM_SLEEP
		static int sh_dmae_suspend(struct device *dev)
		{
		struct sh_dmae_device *shdev = dev_get_drvdata(dev);

		sh_dmae_ctl_stop(shdev);
		return 0;
		}

		@@ -935,7 +935,6 @@ static struct platform_driver sh_dmae_driver = {
		.of_match_table = sh_dmae_of_match,
		},
		.remove = sh_dmae_remove,
		.shutdown = sh_dmae_shutdown,
		};

		static int __init sh_dmae_init(void)