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

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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>
This commit is contained in:
Geert Uytterhoeven 2015-02-26 11:26:34 +01:00 committed by Vinod Koul
parent 3a314f143d
commit b6d1778bc5
1 changed files with 7 additions and 8 deletions
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15
drivers/dma/sh/shdmac.c
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@ -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;
}
@ -929,13 +929,12 @@ static int sh_dmae_remove(struct platform_device *pdev)
}
static struct platform_driver sh_dmae_driver = {
.driver = {
.driver = {
.pm = &sh_dmae_pm,
.name = SH_DMAE_DRV_NAME,
.of_match_table = sh_dmae_of_match,
},
.remove = sh_dmae_remove,
.shutdown = sh_dmae_shutdown,
};
static int __init sh_dmae_init(void)