Re: [PATCH V2] mmc: mmci: add threaded irq to abort DPSM of non-functional state

[Ulf Hansson]

On Wed, 11 Dec 2019 at 14:40, Ludovic Barre <ludovic.Barre@xxxxxx> wrote:
>
> From: Ludovic Barre <ludovic.barre@xxxxxx>
>
> If datatimeout occurs on R1B request, the Data Path State Machine stays
> in busy and is non-functional. Only a reset aborts the DPSM.
>
> Like a reset must be outside of critical section, this patch adds
> threaded irq function to release state machine. In this case,
> the mmc_request_done is called at the end of threaded irq and
> skipped into irq handler.
>
> Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>

Applied for next, thanks!

I took the liberty of doing some minor updates (changelog/comment),
please have a look and let me know if there is something you want me
to change.

And again, apologize for the delays!

Kind regards
Uffe


> ---
> change V2:
>  -check IRQ_WAKE_THREAD only in mmci_cmd_irq error part,
>   to avoid this test in mmci_request_end.
>
> ---
>  drivers/mmc/host/mmci.c | 46 +++++++++++++++++++++++++++++++++++------
>  drivers/mmc/host/mmci.h |  1 +
>  2 files changed, 41 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index 40e72c30ea84..2b91757e3e84 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -1321,6 +1321,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
>         } else if (host->variant->busy_timeout && busy_resp &&
>                    status & MCI_DATATIMEOUT) {
>                 cmd->error = -ETIMEDOUT;
> +               host->irq_action = IRQ_WAKE_THREAD;
>         } else {
>                 cmd->resp[0] = readl(base + MMCIRESPONSE0);
>                 cmd->resp[1] = readl(base + MMCIRESPONSE1);
> @@ -1339,7 +1340,10 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
>                                 return;
>                         }
>                 }
> -               mmci_request_end(host, host->mrq);
> +
> +               if (host->irq_action != IRQ_WAKE_THREAD)
> +                       mmci_request_end(host, host->mrq);
> +
>         } else if (sbc) {
>                 mmci_start_command(host, host->mrq->cmd, 0);
>         } else if (!host->variant->datactrl_first &&
> @@ -1532,9 +1536,9 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>  {
>         struct mmci_host *host = dev_id;
>         u32 status;
> -       int ret = 0;
>
>         spin_lock(&host->lock);
> +       host->irq_action = IRQ_HANDLED;
>
>         do {
>                 status = readl(host->base + MMCISTATUS);
> @@ -1574,12 +1578,41 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>                 if (host->variant->busy_detect_flag)
>                         status &= ~host->variant->busy_detect_flag;
>
> -               ret = 1;
>         } while (status);
>
>         spin_unlock(&host->lock);
>
> -       return IRQ_RETVAL(ret);
> +       return host->irq_action;
> +}
> +
> +/*
> + * mmci_irq_threaded is call if the mmci host need to release state machines
> + * before to terminate the request.
> + * If datatimeout occurs on R1B request, the Data Path State Machine stays
> + * in busy and is non-functional. Only a reset can to abort the DPSM.
> + */
> +static irqreturn_t mmci_irq_threaded(int irq, void *dev_id)
> +{
> +       struct mmci_host *host = dev_id;
> +       unsigned long flags;
> +
> +       if (host->rst) {
> +               reset_control_assert(host->rst);
> +               udelay(2);
> +               reset_control_deassert(host->rst);
> +       }
> +
> +       spin_lock_irqsave(&host->lock, flags);
> +       writel(host->clk_reg, host->base + MMCICLOCK);
> +       writel(host->pwr_reg, host->base + MMCIPOWER);
> +       writel(MCI_IRQENABLE | host->variant->start_err,
> +              host->base + MMCIMASK0);
> +
> +       host->irq_action = IRQ_HANDLED;
> +       mmci_request_end(host, host->mrq);
> +       spin_unlock_irqrestore(&host->lock, flags);
> +
> +       return host->irq_action;
>  }
>
>  static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> @@ -2071,8 +2104,9 @@ static int mmci_probe(struct amba_device *dev,
>                         goto clk_disable;
>         }
>
> -       ret = devm_request_irq(&dev->dev, dev->irq[0], mmci_irq, IRQF_SHARED,
> -                       DRIVER_NAME " (cmd)", host);
> +       ret = devm_request_threaded_irq(&dev->dev, dev->irq[0], mmci_irq,
> +                                       mmci_irq_threaded, IRQF_SHARED,
> +                                       DRIVER_NAME " (cmd)", host);
>         if (ret)
>                 goto clk_disable;
>
> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
> index 158e1231aa23..5e63c0596364 100644
> --- a/drivers/mmc/host/mmci.h
> +++ b/drivers/mmc/host/mmci.h
> @@ -412,6 +412,7 @@ struct mmci_host {
>
>         struct timer_list       timer;
>         unsigned int            oldstat;
> +       u32                     irq_action;
>
>         /* pio stuff */
>         struct sg_mapping_iter  sg_miter;
> --
> 2.17.1
>