Re: [PATCH] mmc: tmio: Fix hang during suspend

From: Ian Molton
Date: Fri Aug 15 2014 - 08:49:29 EST


On Thu, 14 Aug 2014 17:23:53 +0200
Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:

> On R-Car Gen 2, the SDHI registers cannot be accessed while the SDHI
> module clock is disabled. Doing so will cause a lock-up.
>
> When suspending, enable the module clock before disabling the SDHI
> interrupts, and disable the clock again afterwards.

This feels wrong. Why can't interrupts be disabled prior to turning the clock off?

-Ian

> This fixes suspend and resume on r8a7791/koelsch.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> drivers/mmc/host/tmio_mmc_pio.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
> index faf0924e71cb..83192420a7e3 100644
> --- a/drivers/mmc/host/tmio_mmc_pio.c
> +++ b/drivers/mmc/host/tmio_mmc_pio.c
> @@ -1147,8 +1147,18 @@ int tmio_mmc_host_suspend(struct device *dev)
> {
> struct mmc_host *mmc = dev_get_drvdata(dev);
> struct tmio_mmc_host *host = mmc_priv(mmc);
> + struct tmio_mmc_data *pdata = host->pdata;
> +
> + if (pdata->clk_enable) {
> + unsigned int f;
> + pdata->clk_enable(host->pdev, &f);
> + }
>
> tmio_mmc_disable_mmc_irqs(host, TMIO_MASK_ALL);
> +
> + if (pdata->clk_disable)
> + pdata->clk_disable(host->pdev);
> +
> return 0;
> }
> EXPORT_SYMBOL(tmio_mmc_host_suspend);
> --
> 1.9.1
>


--
Ian Molton <ian.molton@xxxxxxxxxxxxxxx>
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