Re: [PATCH 1/5] mmc: sdhci-msm: fix issue with power irq

Vijay Viswanath
2017-08-28T12:33:48Z

On 8/24/2017 1:10 PM, Adrian Hunter wrote:
> On 18/08/17 08:19, Vijay Viswanath wrote:
>> From: Subhash Jadavani <subhashj@codeaurora.org>
>>
>> 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 <subhashj@codeaurora.org>
>> Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
>> ---
>> 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?
>
This is better. Will change the patches to do it this way.
>> + /*
>> + * 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);
>>
>