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    Subject[PATCH 5.1 008/121] mmc: core: Prevent processing SDIO IRQs when the card is suspended
    Date
    From: Ulf Hansson <ulf.hansson@linaro.org>

    commit 83293386bc95cf5e9f0c0175794455835bd1cb4a upstream.

    Processing of SDIO IRQs must obviously be prevented while the card is
    system suspended, otherwise we may end up trying to communicate with an
    uninitialized SDIO card.

    Reports throughout the years shows that this is not only a theoretical
    problem, but a real issue. So, let's finally fix this problem, by keeping
    track of the state for the card and bail out before processing the SDIO
    IRQ, in case the card is suspended.

    Cc: stable@vger.kernel.org
    Reported-by: Douglas Anderson <dianders@chromium.org>
    Tested-by: Douglas Anderson <dianders@chromium.org>
    Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/mmc/core/sdio.c | 13 ++++++++++++-
    drivers/mmc/core/sdio_irq.c | 4 ++++
    2 files changed, 16 insertions(+), 1 deletion(-)

    --- a/drivers/mmc/core/sdio.c
    +++ b/drivers/mmc/core/sdio.c
    @@ -941,6 +941,10 @@ static int mmc_sdio_pre_suspend(struct m
    */
    static int mmc_sdio_suspend(struct mmc_host *host)
    {
    + /* Prevent processing of SDIO IRQs in suspended state. */
    + mmc_card_set_suspended(host->card);
    + cancel_delayed_work_sync(&host->sdio_irq_work);
    +
    mmc_claim_host(host);

    if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host))
    @@ -989,13 +993,20 @@ static int mmc_sdio_resume(struct mmc_ho
    err = sdio_enable_4bit_bus(host->card);
    }

    - if (!err && host->sdio_irqs) {
    + if (err)
    + goto out;
    +
    + /* Allow SDIO IRQs to be processed again. */
    + mmc_card_clr_suspended(host->card);
    +
    + if (host->sdio_irqs) {
    if (!(host->caps2 & MMC_CAP2_SDIO_IRQ_NOTHREAD))
    wake_up_process(host->sdio_irq_thread);
    else if (host->caps & MMC_CAP_SDIO_IRQ)
    host->ops->enable_sdio_irq(host, 1);
    }

    +out:
    mmc_release_host(host);

    host->pm_flags &= ~MMC_PM_KEEP_POWER;
    --- a/drivers/mmc/core/sdio_irq.c
    +++ b/drivers/mmc/core/sdio_irq.c
    @@ -38,6 +38,10 @@ static int process_sdio_pending_irqs(str
    unsigned char pending;
    struct sdio_func *func;

    + /* Don't process SDIO IRQs if the card is suspended. */
    + if (mmc_card_suspended(card))
    + return 0;
    +
    /*
    * Optimization, if there is only 1 function interrupt registered
    * and we know an IRQ was signaled then call irq handler directly.

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