Re: [PATCH] mmc: meson-gx: Convert host->lock to raw spinlock

[Ulf Hansson]

On Mon, Sep 21, 2026 at 9:14 PM Sean Anderson <sanderson@xxxxxxxxx> wrote:
>
> The primary handler for IRQF_ONESHOT interrupts is always run without
> threading, even on PREEMPT_RT. Therefore, we must use a raw spinlock,
> which will never sleep (even on PREEMPT_RT).

Sorry, but I don't quite understand the above. Are you saying that
IRQF_ONESHOT only works with raw spinlocks?

Kind regards
Uffe

>
> Fixes: 066ecde6d826 ("mmc: meson-gx: add SDIO interrupt support")
> Signed-off-by: Sean Anderson <sanderson@xxxxxxxxx>
> ---
>
>  drivers/mmc/host/meson-gx-mmc.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 694bb443d5f3f..d5365c0404cb9 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -176,7 +176,7 @@ struct meson_host {
>
>         bool needs_pre_post_req;
>
> -       spinlock_t lock;
> +       raw_spinlock_t lock;
>  };
>
>  #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
> @@ -953,10 +953,10 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
>         cmd = host->cmd;
>
>         if (status & IRQ_SDIO) {
> -               spin_lock(&host->lock);
> +               raw_spin_lock(&host->lock);
>                 __meson_mmc_enable_sdio_irq(host->mmc, 0);
>                 sdio_signal_irq(host->mmc);
> -               spin_unlock(&host->lock);
> +               raw_spin_unlock(&host->lock);
>                 status &= ~IRQ_SDIO;
>                 if (!status)
>                         return IRQ_HANDLED;
> @@ -1112,9 +1112,9 @@ static void meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
>         struct meson_host *host = mmc_priv(mmc);
>         unsigned long flags;
>
> -       spin_lock_irqsave(&host->lock, flags);
> +       raw_spin_lock_irqsave(&host->lock, flags);
>         __meson_mmc_enable_sdio_irq(mmc, enable);
> -       spin_unlock_irqrestore(&host->lock, flags);
> +       raw_spin_unlock_irqrestore(&host->lock, flags);
>  }
>
>  static void meson_mmc_ack_sdio_irq(struct mmc_host *mmc)
> @@ -1225,7 +1225,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
>         if (ret)
>                 goto err_init_clk;
>
> -       spin_lock_init(&host->lock);
> +       raw_spin_lock_init(&host->lock);
>
>         if (host->dram_access_quirk) {
>                 /* Limit segments to 1 due to low available sram memory */
> ---
> base-commit: 587858367581b9c55c3690f4e63382ad622719d4
> branch: meson_mmc_raw
>
> --
> 2.53.0
>