Re: [PATCH v2 2/2] mmc: sdhci: intel: Disable runtime pm when the sdio_irq is enabled.

[Hans de Goede <hdegoede@redhat.com>]

Hu,

On 21-03-17 13:34, Adrian Hunter wrote:
> On 21/03/17 12:00, Ulf Hansson wrote:
>> On 15 March 2017 at 17:31, Hans de Goede <hdegoede@redhat.com> wrote:
>>> SDIO cards may need clock to send the card interrupt to the host.
>>>
>>> On a cherrytrail tablet with a RTL8723BS wifi chip, without this patch
>>> pinging the tablet results in:
>>>
>>> PING 192.168.1.14 (192.168.1.14) 56(84) bytes of data.
>>> 64 bytes from 192.168.1.14: icmp_seq=1 ttl=64 time=78.6 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=2 ttl=64 time=1760 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=3 ttl=64 time=753 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=4 ttl=64 time=3.88 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=5 ttl=64 time=795 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=6 ttl=64 time=1841 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=7 ttl=64 time=810 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=8 ttl=64 time=1860 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=9 ttl=64 time=812 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=10 ttl=64 time=48.6 ms
>>>
>>> Where as with this patch I get:
>>>
>>> PING 192.168.1.14 (192.168.1.14) 56(84) bytes of data.
>>> 64 bytes from 192.168.1.14: icmp_seq=1 ttl=64 time=3.96 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=2 ttl=64 time=1.97 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=3 ttl=64 time=17.2 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=4 ttl=64 time=2.46 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=5 ttl=64 time=2.83 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=6 ttl=64 time=1.40 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=7 ttl=64 time=2.10 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=8 ttl=64 time=1.40 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=9 ttl=64 time=2.04 ms
>>> 64 bytes from 192.168.1.14: icmp_seq=10 ttl=64 time=1.40 ms
>>>
>>> Cc: Dong Aisheng <b29396@freescale.com>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> ---
>>> Changes in v2:
>>> -New patch replacing "mmc: sdhci: sdio-intel: Set
>>>  SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON quirk"
>>> ---
>>>  drivers/mmc/host/sdhci-acpi.c     | 1 +
>>>  drivers/mmc/host/sdhci-pci-core.c | 1 +
>>>  drivers/mmc/host/sdhci.c          | 6 ++++++
>>>  drivers/mmc/host/sdhci.h          | 2 ++
>>>  4 files changed, 10 insertions(+)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
>>> index 237f318..53b431a 100644
>>> --- a/drivers/mmc/host/sdhci-acpi.c
>>> +++ b/drivers/mmc/host/sdhci-acpi.c
>>> @@ -288,6 +288,7 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_int_emmc = {
>>>  static const struct sdhci_acpi_slot sdhci_acpi_slot_int_sdio = {
>>>         .quirks  = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
>>>         .quirks2 = SDHCI_QUIRK2_HOST_OFF_CARD_ON |
>>> +                  SDHCI_QUIRK2_SDIO_IRQ_NO_RUNTIME_PM |
>>>                    SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
>>>         .caps    = MMC_CAP_NONREMOVABLE | MMC_CAP_POWER_OFF_CARD |
>>>                    MMC_CAP_WAIT_WHILE_BUSY,
>>> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
>>> index 982b3e3..a3b242e 100644
>>> --- a/drivers/mmc/host/sdhci-pci-core.c
>>> +++ b/drivers/mmc/host/sdhci-pci-core.c
>>> @@ -498,6 +498,7 @@ static const struct sdhci_pci_fixes sdhci_ni_byt_sdio = {
>>>  static const struct sdhci_pci_fixes sdhci_intel_byt_sdio = {
>>>         .quirks         = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
>>>         .quirks2        = SDHCI_QUIRK2_HOST_OFF_CARD_ON |
>>> +                       SDHCI_QUIRK2_SDIO_IRQ_NO_RUNTIME_PM |
>>>                         SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
>>>         .allow_runtime_pm = true,
>>>         .probe_slot     = byt_sdio_probe_slot,
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index 6fdd7a7..59c5cad 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -1828,6 +1828,9 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
>>>         struct sdhci_host *host = mmc_priv(mmc);
>>>         unsigned long flags;
>>>
>>> +       if ((host->quirks2 & SDHCI_QUIRK2_SDIO_IRQ_NO_RUNTIME_PM) && enable)
>>> +               pm_runtime_get(host->mmc->parent);
>>
>> There are currently no sdhci variant for any SoC that implements
>> wakeup support in runtime suspend for SDIO irqs. In other words, it
>> seems all sdhci hosts suffers from the same problem.
>
> There might still be drivers that expect SDIO interrupts during
> runtime suspend, considering this patch:
>
> 	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=be138554a7923658ded799b0e8794d9c1d08a6e5

Right, I do agree with Ulf that disabling runtime_pm while an
sdio-irq is requested should probably be the default, so maybe
revert the quirk and make it allow runtime pm if set, e.g. :

	if (enable && !(host->quirks2 & SDHCI_QUIRK2_SDIO_IRQ_RUNTIME_PM))
		pm_runtime_get(host->mmc->parent)

And then add the quirk to drivers/mmc/host/sdhci-esdhc-imx.c ?

Regards,

Hans



>
>>
>> I imagine there are vendor trees implementing wakeups, however until
>> we see such code being pushed upstream, I suggest we make this the
>> default behavior instead of using a quirk.
>>
>>> +
>>>         spin_lock_irqsave(&host->lock, flags);
>>>         if (enable)
>>>                 host->flags |= SDHCI_SDIO_IRQ_ENABLED;
>>> @@ -1836,6 +1839,9 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
>>>
>>>         sdhci_enable_sdio_irq_nolock(host, enable);
>>>         spin_unlock_irqrestore(&host->lock, flags);
>>> +
>>> +       if ((host->quirks2 & SDHCI_QUIRK2_SDIO_IRQ_NO_RUNTIME_PM) && !enable)
>>> +               pm_runtime_put(host->mmc->parent);
>>>  }
>>>
>>>  static int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
>>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>>> index edf3adf..b72c38d 100644
>>> --- a/drivers/mmc/host/sdhci.h
>>> +++ b/drivers/mmc/host/sdhci.h
>>> @@ -427,6 +427,8 @@ struct sdhci_host {
>>>  #define SDHCI_QUIRK2_ACMD23_BROKEN                     (1<<14)
>>>  /* Broken Clock divider zero in controller */
>>>  #define SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN             (1<<15)
>>> +/* Must not runtime suspend when sdio_irq is enabled */
>>> +#define SDHCI_QUIRK2_SDIO_IRQ_NO_RUNTIME_PM            (1<<16)
>>>
>>>         int irq;                /* Device IRQ */
>>>         void __iomem *ioaddr;   /* Mapped address */
>>> --
>>> 2.9.3
>>>
>>
>> Kind regards
>> Uffe
>>
>