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 ?
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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