On Sun, Jan 23, 2011 at 9:17 PM, Philip Rakity <prakity@xxxxxxxxxxx> wrote:
>
> I am confused. Your patch modifiies
>
> sdhci_suspend_host () to
>>>> + sdhci_clear_set_irqs(host, SDHCI_INT_ALL_MASK, 0);
>>>
>
>
>
> #define SDHCI_INT_ALL_MASK ((unsigned int)-1)
>
> static void sdhci_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set)
> {
> u32 ier;
>
> ier = sdhci_readl(host, SDHCI_INT_ENABLE);
> ier &= ~clear;
> ier |= set;
> sdhci_writel(host, ier, SDHCI_INT_ENABLE);
> sdhci_writel(host, ier, SDHCI_SIGNAL_ENABLE);
> }
>
>
> The code clears all the interrupts. How is a card insert detected ?
In sdhci.c, sdhci_disable_card_detection is called in suspend_host,
and card does not be detected when cpu is suspended.
>
>
>
>
> On Jan 23, 2011, at 6:10 PM, zhangfei gao wrote:
>
>> On Fri, Jan 21, 2011 at 2:33 PM, Nicolas Pitre <nico@xxxxxxxxxxx> wrote:
>>> On Fri, 21 Jan 2011, zhangfei gao wrote:
>>>
>>>>> From b7be39e0bbac3950057078ac66900ebc0871f77e Mon Sep 17 00:00:00 2001
>>>> From: Zhangfei Gao <zhangfei.gao@xxxxxxxxxxx>
>>>> Date: Fri, 21 Jan 2011 18:02:47 -0500
>>>> Subject: [PATCH] mmc: clear all interrupt in suspend before free_irq
>>>>
>>>> When debugging wifi host sleep, race condition about
>>>> SDHCI_INT_CARD_INT happens.
>>>> Host free_irq in suspend and request_irq when resume back.
>>>> However SDHCI_INT_CARD_INT is not cleared, so interrupt will
>>>> immediately happen after request_irq.
>>>> mmc_signal_sdio_irq will be called and wakeup sdio_irq_thread.
>>>> As a result irq_handler in sdio driver is called even before host resume back.
>>>>
>>>> The correct case is mmc_sdio_resume calls mmc_signal_sdio_irq to
>>>> wakeup sdio_irq_thread
>>>>
>>>> Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxxx>
>>>
>>> That makes sense, as long as the masking of interrupts doesn't prevent
>>> a SDIO card interrupt from waking up the host system.
>>
>> Thanks Nicolas for comments
>>
>> Masking interrupt does not impact wake up cpu.
>> 1. irq is already freed in suspend, and request again when resume backed
>> 2. cpu is wake up first, then irq service is handled, so irq does not
>> impact cpu wake up or not.
>> 3. mmc_signal_sdio_irq is serviced in mmc_sdio_resume.
>>
>>>
>>>
>>>> ---
>>>> drivers/mmc/host/sdhci.c | 1 +
>>>> 1 files changed, 1 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>>> index aacd78c..97074ae 100644
>>>> --- a/drivers/mmc/host/sdhci.c
>>>> +++ b/drivers/mmc/host/sdhci.c
>>>> @@ -1707,6 +1707,7 @@ int sdhci_suspend_host(struct sdhci_host *host,
>>>> pm_message_t state)
>>>> ret = mmc_suspend_host(host->mmc);
>>>> if (ret)
>>>> return ret;
>>>> + sdhci_clear_set_irqs(host, SDHCI_INT_ALL_MASK, 0);
>>>>
>>>> free_irq(host->irq, host);
>>>>
>>>> --
>>>> 1.7.0.4
>>>>
>>>
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>
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