[PATCH 1/2] mmc: sdhci-pltfm: fix abort due to missing runtime PM

[Stefan Agner]

On 2014-12-02 17:47, Stefan Agner wrote:
> When entering suspend while the device is in runtime PM, the
> sdhci_[suspend|resume]_host function are called without taking
> care of runtime PM. On Vybrid SoC this leads to external abort
> since during runtime suspend, the clocks for this peripheral
> are disabled.
> 
> [   37.772967] Unhandled fault: imprecise external abort (0x1c06) at 0x76f5f000
> [   37.780304] Internal error: : 1c06 [#1] ARM
> [   37.784670] Modules linked in:
> [   37.787908] CPU: 0 PID: 428 Comm: sh Not tainted
> 3.18.0-rc5-00119-geefd097-dirty #1540
> [   37.796142] task: 8e246c00 ti: 8ca6c000 task.ti: 8ca6c000
> [   37.801785] PC is at esdhc_writel_le+0x40/0xec
> [   37.806431] LR is at sdhci_set_card_detection+0xe0/0xe4
> [   37.811877] pc : [<803f0584>]    lr : [<803eaaa0>]    psr: 400f0013
> [   37.811877] sp : 8ca6dd28  ip : 00000001  fp : 8ca6dd3c
> [   37.823766] r10: 807a233c  r9 : 00000000  r8 : 8e8b7210
> [   37.829194] r7 : 802d8a08  r6 : 8082e928  r5 : 00000000  r4 : 00000002
> [   37.835974] r3 : 8ea34e90  r2 : 00000038  r1 : 00000000  r0 : 8ea32ac0
> ...
> 
> Signed-off-by: Stefan Agner <stefan at agner.ch>
> ---
> Not really sure this is the right place to fix this. The function now
> ended up to be identically to the implementations in sdhci-pxav3.c...

Any thoughts on this?

> 
>  drivers/mmc/host/sdhci-pltfm.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-pltfm.c b/drivers/mmc/host/sdhci-pltfm.c
> index c5b01d6..0bc864e 100644
> --- a/drivers/mmc/host/sdhci-pltfm.c
> +++ b/drivers/mmc/host/sdhci-pltfm.c
> @@ -31,6 +31,7 @@
>  #include <linux/err.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/pm_runtime.h>
>  #ifdef CONFIG_PPC
>  #include <asm/machdep.h>
>  #endif
> @@ -237,17 +238,29 @@ EXPORT_SYMBOL_GPL(sdhci_pltfm_unregister);
>  #ifdef CONFIG_PM
>  int sdhci_pltfm_suspend(struct device *dev)
>  {
> +	int ret;
>  	struct sdhci_host *host = dev_get_drvdata(dev);
>  
> -	return sdhci_suspend_host(host);
> +	pm_runtime_get_sync(dev);
> +	ret = sdhci_suspend_host(host);
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_autosuspend(dev);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(sdhci_pltfm_suspend);
>  
>  int sdhci_pltfm_resume(struct device *dev)
>  {
> +	int ret;
>  	struct sdhci_host *host = dev_get_drvdata(dev);
>  
> -	return sdhci_resume_host(host);
> +	pm_runtime_get_sync(dev);
> +	ret = sdhci_resume_host(host);
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_autosuspend(dev);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(sdhci_pltfm_resume);