On 18/08/17 08:19, Vijay Viswanath wrote:
> From: Subhash Jadavani <[email protected]>
> 
> SDCC controller reset (SW_RST) during probe may trigger power irq if
> previous status of PWRCTL was either BUS_ON or IO_HIGH_V. So before we
> enable the power irq interrupt in GIC (by registering the interrupt
> handler), we need to ensure that any pending power irq interrupt status
> is acknowledged otherwise power irq interrupt handler would be fired
> prematurely.
> 
> Signed-off-by: Subhash Jadavani <[email protected]>
> Signed-off-by: Vijay Viswanath <[email protected]>
> ---
>  drivers/mmc/host/sdhci-msm.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 9d601dc..0957199 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -1128,6 +1128,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>       u16 host_version, core_minor;
>       u32 core_version, config;
>       u8 core_major;
> +     u32 irq_status, irq_ctl;
>  
>       host = sdhci_pltfm_init(pdev, &sdhci_msm_pdata, sizeof(*msm_host));
>       if (IS_ERR(host))
> @@ -1250,6 +1251,28 @@ static int sdhci_msm_probe(struct platform_device 
> *pdev)
>                              CORE_VENDOR_SPEC_CAPABILITIES0);
>       }
>  
> +     /*
> +      * Power on reset state may trigger power irq if previous status of
> +      * PWRCTL was either BUS_ON or IO_HIGH_V. So before enabling pwr irq
> +      * interrupt in GIC, any pending power irq interrupt should be
> +      * acknowledged. Otherwise power irq interrupt handler would be
> +      * fired prematurely.
> +      */
> +
> +     irq_status = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
> +     writel_relaxed(irq_status, msm_host->core_mem + CORE_PWRCTL_CLEAR);
> +     irq_ctl = readl_relaxed(msm_host->core_mem + CORE_PWRCTL_CTL);
> +     if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF))
> +             irq_ctl |= CORE_PWRCTL_BUS_SUCCESS;
> +     if (irq_status & (CORE_PWRCTL_IO_HIGH | CORE_PWRCTL_IO_LOW))
> +             irq_ctl |= CORE_PWRCTL_IO_SUCCESS;
> +     writel_relaxed(irq_ctl, msm_host->core_mem + CORE_PWRCTL_CTL);

This looks a lot like sdhci_msm_voltage_switch().  Can clearing the
interrupt be a common function?

> +     /*
> +      * Ensure that above writes are propogated before interrupt enablement
> +      * in GIC.
> +      */
> +     mb();
> +
>       /* Setup IRQ for handling power/voltage tasks with PMIC */
>       msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
>       if (msm_host->pwr_irq < 0) {
> @@ -1259,6 +1282,9 @@ static int sdhci_msm_probe(struct platform_device *pdev)
>               goto clk_disable;
>       }
>  
> +     /* Enable pwr irq interrupts */
> +     writel_relaxed(INT_MASK, msm_host->core_mem + CORE_PWRCTL_MASK);
> +
>       ret = devm_request_threaded_irq(&pdev->dev, msm_host->pwr_irq, NULL,
>                                       sdhci_msm_pwr_irq, IRQF_ONESHOT,
>                                       dev_name(&pdev->dev), host);
> 

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