* [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver
@ 2020-02-20 6:45 Shaik Sajida Bhanu
2020-02-27 14:30 ` Veerabhadrarao Badiganti
2020-03-04 15:34 ` Ulf Hansson
0 siblings, 2 replies; 7+ messages in thread
From: Shaik Sajida Bhanu @ 2020-02-20 6:45 UTC (permalink / raw)
To: adrian.hunter, ulf.hansson, robh+dt, mka
Cc: asutoshd, swboyd, stummala, sayalil, cang, vbadigan, rampraka,
linux-mmc, linux-kernel, linux-arm-msm, devicetree, agross,
bjorn.andersson, Shaik Sajida Bhanu
The existing suspend/resume callbacks of sdhci-msm driver are just
gating/un-gating the clocks. During suspend cycle more can be done
like disabling controller, disabling card detection, enabling wake-up events.
So updating the system pm callbacks for performing these extra
actions besides controlling the clocks.
Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
---
Changes since V3:
Invoking sdhci & cqhci resume if sdhci_host_suspend fails.
Removed condition check before invoking cqhci_resume since its a dummy function.
Changes since V2:
Removed disabling/enabling pwr-irq from system pm ops.
Changes since V1:
Invoking pm_runtime_force_suspend/resume instead of
sdhci_msm_runtime_suepend/resume.
---
drivers/mmc/host/sdhci-msm.c | 47 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 45 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 3955fa5d..3559b50 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -2159,9 +2159,52 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
return 0;
}
+static int sdhci_msm_suspend(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+ int ret;
+
+ if (host->mmc->caps2 & MMC_CAP2_CQE) {
+ ret = cqhci_suspend(host->mmc);
+ if (ret)
+ return ret;
+ }
+
+ ret = sdhci_suspend_host(host);
+ if (ret)
+ goto resume_cqhci;
+
+ ret = pm_runtime_force_suspend(dev);
+ if (!ret)
+ return ret;
+
+ sdhci_resume_host(host);
+
+resume_cqhci:
+ cqhci_resume(host->mmc);
+ return ret;
+}
+
+static int sdhci_msm_resume(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pm_runtime_force_resume(dev);
+ if (ret)
+ return ret;
+
+ ret = sdhci_resume_host(host);
+ if (ret < 0)
+ return ret;
+
+ ret = cqhci_resume(host->mmc);
+ return ret;
+}
+
static const struct dev_pm_ops sdhci_msm_pm_ops = {
- SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
- pm_runtime_force_resume)
+ SET_SYSTEM_SLEEP_PM_OPS(sdhci_msm_suspend,
+ sdhci_msm_resume)
SET_RUNTIME_PM_OPS(sdhci_msm_runtime_suspend,
sdhci_msm_runtime_resume,
NULL)
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver
2020-02-20 6:45 [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver Shaik Sajida Bhanu
@ 2020-02-27 14:30 ` Veerabhadrarao Badiganti
2020-03-04 15:34 ` Ulf Hansson
1 sibling, 0 replies; 7+ messages in thread
From: Veerabhadrarao Badiganti @ 2020-02-27 14:30 UTC (permalink / raw)
To: Shaik Sajida Bhanu, adrian.hunter, ulf.hansson, robh+dt, mka
Cc: asutoshd, swboyd, stummala, sayalil, cang, rampraka, linux-mmc,
linux-kernel, linux-arm-msm, devicetree, agross, bjorn.andersson
Hi Sajida,
On 2/20/2020 12:15 PM, Shaik Sajida Bhanu wrote:
> The existing suspend/resume callbacks of sdhci-msm driver are just
> gating/un-gating the clocks. During suspend cycle more can be done
> like disabling controller, disabling card detection, enabling wake-up events.
>
> So updating the system pm callbacks for performing these extra
> actions besides controlling the clocks.
>
> Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> ---
> Changes since V3:
> Invoking sdhci & cqhci resume if sdhci_host_suspend fails.
> Removed condition check before invoking cqhci_resume since its a dummy function.
>
> Changes since V2:
> Removed disabling/enabling pwr-irq from system pm ops.
>
> Changes since V1:
> Invoking pm_runtime_force_suspend/resume instead of
> sdhci_msm_runtime_suepend/resume.
> ---
> drivers/mmc/host/sdhci-msm.c | 47 ++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 45 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 3955fa5d..3559b50 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -2159,9 +2159,52 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
> return 0;
> }
>
> +static int sdhci_msm_suspend(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + int ret;
> +
> + if (host->mmc->caps2 & MMC_CAP2_CQE) {
> + ret = cqhci_suspend(host->mmc);
> + if (ret)
> + return ret;
> + }
> +
> + ret = sdhci_suspend_host(host);
> + if (ret)
> + goto resume_cqhci;
> +
> + ret = pm_runtime_force_suspend(dev);
> + if (!ret)
> + return ret;
> +
> + sdhci_resume_host(host);
> +
> +resume_cqhci:
> + cqhci_resume(host->mmc);
> + return ret;
> +}
> +
> +static int sdhci_msm_resume(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pm_runtime_force_resume(dev);
> + if (ret)
> + return ret;
> +
> + ret = sdhci_resume_host(host);
I'm observing an issue with this change.
After this step, i find interrupt enable register is zero (even though
it's getting set in sdhci_resume_host()) and
resulting in request timeout for very first command in resume path.
Until its root caused, please hold back this change.
> + if (ret < 0)
> + return ret;
> +
> + ret = cqhci_resume(host->mmc);
> + return ret;
> +}
> +
> static const struct dev_pm_ops sdhci_msm_pm_ops = {
> - SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> - pm_runtime_force_resume)
> + SET_SYSTEM_SLEEP_PM_OPS(sdhci_msm_suspend,
> + sdhci_msm_resume)
> SET_RUNTIME_PM_OPS(sdhci_msm_runtime_suspend,
> sdhci_msm_runtime_resume,
> NULL)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver
2020-02-20 6:45 [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver Shaik Sajida Bhanu
2020-02-27 14:30 ` Veerabhadrarao Badiganti
@ 2020-03-04 15:34 ` Ulf Hansson
[not found] ` <158334039680.7173.16159724456027777605@swboyd.mtv.corp.google.com>
1 sibling, 1 reply; 7+ messages in thread
From: Ulf Hansson @ 2020-03-04 15:34 UTC (permalink / raw)
To: Shaik Sajida Bhanu
Cc: Adrian Hunter, Rob Herring, Matthias Kaehlcke, Asutosh Das,
Stephen Boyd, Sahitya Tummala, Sayali Lokhande, cang,
Veerabhadrarao Badiganti, Ram Prakash Gupta, linux-mmc,
Linux Kernel Mailing List, linux-arm-msm, DTML, Andy Gross,
Bjorn Andersson
On Thu, 20 Feb 2020 at 07:45, Shaik Sajida Bhanu <sbhanu@codeaurora.org> wrote:
>
> The existing suspend/resume callbacks of sdhci-msm driver are just
> gating/un-gating the clocks. During suspend cycle more can be done
> like disabling controller, disabling card detection, enabling wake-up events.
>
> So updating the system pm callbacks for performing these extra
> actions besides controlling the clocks.
>
> Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> ---
> Changes since V3:
> Invoking sdhci & cqhci resume if sdhci_host_suspend fails.
> Removed condition check before invoking cqhci_resume since its a dummy function.
>
> Changes since V2:
> Removed disabling/enabling pwr-irq from system pm ops.
>
> Changes since V1:
> Invoking pm_runtime_force_suspend/resume instead of
> sdhci_msm_runtime_suepend/resume.
> ---
> drivers/mmc/host/sdhci-msm.c | 47 ++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 45 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 3955fa5d..3559b50 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -2159,9 +2159,52 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
> return 0;
> }
>
> +static int sdhci_msm_suspend(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + int ret;
> +
> + if (host->mmc->caps2 & MMC_CAP2_CQE) {
> + ret = cqhci_suspend(host->mmc);
> + if (ret)
> + return ret;
> + }
> +
> + ret = sdhci_suspend_host(host);
> + if (ret)
> + goto resume_cqhci;
sdhci_suspend_host() can't be called on a device that has been runtime
suspended, as that would lead to accessing device registers when
clocks/PM domains are gated.
Depending on how the corresponding cqhci device is managed from a
runtime PM point of view, it could also be problematic to call
cqhci_suspend().
> +
> + ret = pm_runtime_force_suspend(dev);
It looks to me that perhaps you could make use of solely
pm_runtime_force_suspend(), then just skip calling
sdhci_suspend|resume_host() altogether. Do you think that could work?
And vice versa for sdhci_msm_resume(), of course.
> + if (!ret)
> + return ret;
> +
> + sdhci_resume_host(host);
> +
> +resume_cqhci:
> + cqhci_resume(host->mmc);
> + return ret;
> +}
> +
> +static int sdhci_msm_resume(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pm_runtime_force_resume(dev);
> + if (ret)
> + return ret;
> +
> + ret = sdhci_resume_host(host);
> + if (ret < 0)
> + return ret;
> +
> + ret = cqhci_resume(host->mmc);
> + return ret;
> +}
> +
> static const struct dev_pm_ops sdhci_msm_pm_ops = {
> - SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> - pm_runtime_force_resume)
> + SET_SYSTEM_SLEEP_PM_OPS(sdhci_msm_suspend,
> + sdhci_msm_resume)
> SET_RUNTIME_PM_OPS(sdhci_msm_runtime_suspend,
> sdhci_msm_runtime_resume,
> NULL)
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>
Kind regards
Uffe
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver
[not found] ` <158334039680.7173.16159724456027777605@swboyd.mtv.corp.google.com>
@ 2020-03-05 13:56 ` Veerabhadrarao Badiganti
2020-03-06 10:07 ` Ulf Hansson
1 sibling, 0 replies; 7+ messages in thread
From: Veerabhadrarao Badiganti @ 2020-03-05 13:56 UTC (permalink / raw)
To: Stephen Boyd, Shaik Sajida Bhanu, Ulf Hansson
Cc: Adrian Hunter, Rob Herring, Matthias Kaehlcke, Asutosh Das,
Sahitya Tummala, Sayali Lokhande, cang, Ram Prakash Gupta,
linux-mmc, Linux Kernel Mailing List, linux-arm-msm, DTML,
Andy Gross, Bjorn Andersson
On 3/4/2020 10:16 PM, Stephen Boyd wrote:
> Quoting Ulf Hansson (2020-03-04 07:34:29)
>> On Thu, 20 Feb 2020 at 07:45, Shaik Sajida Bhanu <sbhanu@codeaurora.org> wrote:
>>> The existing suspend/resume callbacks of sdhci-msm driver are just
>>> gating/un-gating the clocks. During suspend cycle more can be done
>>> like disabling controller, disabling card detection, enabling wake-up events.
>>>
>>> So updating the system pm callbacks for performing these extra
>>> actions besides controlling the clocks.
>>>
>>> Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
>>> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
>>> ---
>>> Changes since V3:
>>> Invoking sdhci & cqhci resume if sdhci_host_suspend fails.
>>> Removed condition check before invoking cqhci_resume since its a dummy function.
>>>
>>> Changes since V2:
>>> Removed disabling/enabling pwr-irq from system pm ops.
>>>
>>> Changes since V1:
>>> Invoking pm_runtime_force_suspend/resume instead of
>>> sdhci_msm_runtime_suepend/resume.
>>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>>> index 3955fa5d..3559b50 100644
>>> --- a/drivers/mmc/host/sdhci-msm.c
>>> +++ b/drivers/mmc/host/sdhci-msm.c
>>> @@ -2159,9 +2159,52 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
> [...]
>>> +
>>> + ret = sdhci_suspend_host(host);
>>> + if (ret)
>>> + goto resume_cqhci;
>> sdhci_suspend_host() can't be called on a device that has been runtime
>> suspended, as that would lead to accessing device registers when
>> clocks/PM domains are gated.
>>
>> Depending on how the corresponding cqhci device is managed from a
>> runtime PM point of view, it could also be problematic to call
>> cqhci_suspend().
> There seems to be another patch floating around here[1] that is an
> attempt at a fix to this patch. They should probably be combined so that
> it's not confusing what's going on.
The other fix is altogether different. It is the fix for the issue seen
with run-time pm.
whereas this change is for system pm.
>>> +
>>> + ret = pm_runtime_force_suspend(dev);
>> It looks to me that perhaps you could make use of solely
>> pm_runtime_force_suspend(), then just skip calling
>> sdhci_suspend|resume_host() altogether. Do you think that could work?
> Does that do all the things the commit text mentions is desired for
> system suspend?
>
>>> like disabling controller, disabling card detection, enabling wake-up events.
> [1] https://lore.kernel.org/linux-arm-msm/1583322863-21790-1-git-send-email-vbadigan@codeaurora.org/
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver
[not found] ` <158334039680.7173.16159724456027777605@swboyd.mtv.corp.google.com>
2020-03-05 13:56 ` Veerabhadrarao Badiganti
@ 2020-03-06 10:07 ` Ulf Hansson
[not found] ` <158463974696.152100.8345578995373250448@swboyd.mtv.corp.google.com>
1 sibling, 1 reply; 7+ messages in thread
From: Ulf Hansson @ 2020-03-06 10:07 UTC (permalink / raw)
To: Stephen Boyd, Shaik Sajida Bhanu
Cc: Adrian Hunter, Rob Herring, Matthias Kaehlcke, Asutosh Das,
Sahitya Tummala, Sayali Lokhande, cang, Veerabhadrarao Badiganti,
Ram Prakash Gupta, linux-mmc, Linux Kernel Mailing List,
linux-arm-msm, DTML, Andy Gross, Bjorn Andersson
On Wed, 4 Mar 2020 at 17:46, Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Ulf Hansson (2020-03-04 07:34:29)
> > On Thu, 20 Feb 2020 at 07:45, Shaik Sajida Bhanu <sbhanu@codeaurora.org> wrote:
> > >
> > > The existing suspend/resume callbacks of sdhci-msm driver are just
> > > gating/un-gating the clocks. During suspend cycle more can be done
> > > like disabling controller, disabling card detection, enabling wake-up events.
> > >
> > > So updating the system pm callbacks for performing these extra
> > > actions besides controlling the clocks.
> > >
> > > Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
> > > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> > > ---
> > > Changes since V3:
> > > Invoking sdhci & cqhci resume if sdhci_host_suspend fails.
> > > Removed condition check before invoking cqhci_resume since its a dummy function.
> > >
> > > Changes since V2:
> > > Removed disabling/enabling pwr-irq from system pm ops.
> > >
> > > Changes since V1:
> > > Invoking pm_runtime_force_suspend/resume instead of
> > > sdhci_msm_runtime_suepend/resume.
> > > diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> > > index 3955fa5d..3559b50 100644
> > > --- a/drivers/mmc/host/sdhci-msm.c
> > > +++ b/drivers/mmc/host/sdhci-msm.c
> > > @@ -2159,9 +2159,52 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
> [...]
> > > +
> > > + ret = sdhci_suspend_host(host);
> > > + if (ret)
> > > + goto resume_cqhci;
> >
> > sdhci_suspend_host() can't be called on a device that has been runtime
> > suspended, as that would lead to accessing device registers when
> > clocks/PM domains are gated.
> >
> > Depending on how the corresponding cqhci device is managed from a
> > runtime PM point of view, it could also be problematic to call
> > cqhci_suspend().
>
> There seems to be another patch floating around here[1] that is an
> attempt at a fix to this patch. They should probably be combined so that
> it's not confusing what's going on.
Yeah, it would be easier if these are discussed together.
>
> >
> > > +
> > > + ret = pm_runtime_force_suspend(dev);
> >
> > It looks to me that perhaps you could make use of solely
> > pm_runtime_force_suspend(), then just skip calling
> > sdhci_suspend|resume_host() altogether. Do you think that could work?
>
> Does that do all the things the commit text mentions is desired for
> system suspend?
No. :-)
But why is system wakeup needed for an eMMC card?
>
> > > like disabling controller, disabling card detection, enabling wake-up events.
>
> [1] https://lore.kernel.org/linux-arm-msm/1583322863-21790-1-git-send-email-vbadigan@codeaurora.org/
Kind regards
Uffe
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver
[not found] ` <158463974696.152100.8345578995373250448@swboyd.mtv.corp.google.com>
@ 2020-03-20 10:22 ` Ulf Hansson
[not found] ` <158690616084.105027.4255268086188981149@swboyd.mtv.corp.google.com>
0 siblings, 1 reply; 7+ messages in thread
From: Ulf Hansson @ 2020-03-20 10:22 UTC (permalink / raw)
To: Stephen Boyd
Cc: Shaik Sajida Bhanu, Adrian Hunter, Rob Herring,
Matthias Kaehlcke, Asutosh Das, Sahitya Tummala, Sayali Lokhande,
cang, Veerabhadrarao Badiganti, Ram Prakash Gupta, linux-mmc,
Linux Kernel Mailing List, linux-arm-msm, DTML, Andy Gross,
Bjorn Andersson
On Thu, 19 Mar 2020 at 18:42, Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Ulf Hansson (2020-03-06 02:07:41)
> > On Wed, 4 Mar 2020 at 17:46, Stephen Boyd <swboyd@chromium.org> wrote:
> > >
> > > Quoting Ulf Hansson (2020-03-04 07:34:29)
> > > > On Thu, 20 Feb 2020 at 07:45, Shaik Sajida Bhanu <sbhanu@codeaurora.org> wrote:
> > > > >
> > > > > The existing suspend/resume callbacks of sdhci-msm driver are just
> > > > > gating/un-gating the clocks. During suspend cycle more can be done
> > > > > like disabling controller, disabling card detection, enabling wake-up events.
> > > > >
> > > > > So updating the system pm callbacks for performing these extra
> > > > > actions besides controlling the clocks.
> > > > >
> > > > > Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
> > > > > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> > > > > ---
> [...]
> >
> > >
> > > >
> > > > > +
> > > > > + ret = pm_runtime_force_suspend(dev);
> > > >
> > > > It looks to me that perhaps you could make use of solely
> > > > pm_runtime_force_suspend(), then just skip calling
> > > > sdhci_suspend|resume_host() altogether. Do you think that could work?
> > >
> > > Does that do all the things the commit text mentions is desired for
> > > system suspend?
> >
> > No. :-)
> >
> > But why is system wakeup needed for an eMMC card?
> >
>
> I don't know if system wakeup is needed for an eMMC card. Probably only
> if you plug in a card and some daemon wants to wake up and probe the
> card for auto-play or something like that? Seems possible so might as
> well expose the CD gpio as a wakeup in that case and let userspace
> decide if it wants to do that.
Right, card detect IRQs could be useful for system wakeups.
I assume you are using a GPIO IRQ for that, which is easily managed,
as the runtime PM status of the mmc controller is irrelevant when
configuring the GPIO IRQ as wakeup.
We even have a helper for doing this, mmc_gpio_set_cd_wake().
>
> Is runtime suspended state the same as system suspended state here
> though? The commit text seems to imply that only clks are disabled when
> it's desirable to disable the entire controller. I'm still fuzzy on how
> runtime PM and system PM interact because it seems to have changed since
> I looked last a few years ago. If the driver can stay in a runtime
> suspended state across system suspend then I'm all for it. That would
> save time for system PM transitions.
In most cases this should be possible. And so far, for this case, I
haven't found a good reason to why it shouldn't work.
Although, perhaps we need to improve some of the sdhci's library
functions for PM, to better support this.
Kind regards
Uffe
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver
[not found] ` <158690616084.105027.4255268086188981149@swboyd.mtv.corp.google.com>
@ 2020-04-20 9:29 ` Ulf Hansson
0 siblings, 0 replies; 7+ messages in thread
From: Ulf Hansson @ 2020-04-20 9:29 UTC (permalink / raw)
To: Stephen Boyd
Cc: Shaik Sajida Bhanu, Adrian Hunter, Rob Herring,
Matthias Kaehlcke, Asutosh Das, Sahitya Tummala, Sayali Lokhande,
cang, Veerabhadrarao Badiganti, Ram Prakash Gupta, linux-mmc,
Linux Kernel Mailing List, linux-arm-msm, DTML, Andy Gross,
Bjorn Andersson
On Wed, 15 Apr 2020 at 01:16, Stephen Boyd <swboyd@chromium.org> wrote:
>
> Quoting Ulf Hansson (2020-03-20 03:22:01)
> > On Thu, 19 Mar 2020 at 18:42, Stephen Boyd <swboyd@chromium.org> wrote:
> > >
> > > Quoting Ulf Hansson (2020-03-06 02:07:41)
> > > > On Wed, 4 Mar 2020 at 17:46, Stephen Boyd <swboyd@chromium.org> wrote:
> > > > >
> > > > > Quoting Ulf Hansson (2020-03-04 07:34:29)
> > > > > > On Thu, 20 Feb 2020 at 07:45, Shaik Sajida Bhanu <sbhanu@codeaurora.org> wrote:
> > > > > > >
> > > > > > > The existing suspend/resume callbacks of sdhci-msm driver are just
> > > > > > > gating/un-gating the clocks. During suspend cycle more can be done
> > > > > > > like disabling controller, disabling card detection, enabling wake-up events.
> > > > > > >
> > > > > > > So updating the system pm callbacks for performing these extra
> > > > > > > actions besides controlling the clocks.
> > > > > > >
> > > > > > > Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>
> > > > > > > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> > > > > > > ---
> > > [...]
> > > >
> > > > >
> > > > > >
> > > > > > > +
> > > > > > > + ret = pm_runtime_force_suspend(dev);
> > > > > >
> > > > > > It looks to me that perhaps you could make use of solely
> > > > > > pm_runtime_force_suspend(), then just skip calling
> > > > > > sdhci_suspend|resume_host() altogether. Do you think that could work?
> > > > >
> > > > > Does that do all the things the commit text mentions is desired for
> > > > > system suspend?
> > > >
> > > > No. :-)
> > > >
> > > > But why is system wakeup needed for an eMMC card?
> > > >
> > >
> > > I don't know if system wakeup is needed for an eMMC card. Probably only
> > > if you plug in a card and some daemon wants to wake up and probe the
> > > card for auto-play or something like that? Seems possible so might as
> > > well expose the CD gpio as a wakeup in that case and let userspace
> > > decide if it wants to do that.
> >
> > Right, card detect IRQs could be useful for system wakeups.
> >
> > I assume you are using a GPIO IRQ for that, which is easily managed,
> > as the runtime PM status of the mmc controller is irrelevant when
> > configuring the GPIO IRQ as wakeup.
> >
> > We even have a helper for doing this, mmc_gpio_set_cd_wake().
>
> Right. Maybe mmc_gpio_set_cd_wake() needs to be called from somewhere in
> the sdhci core?
Yes, that seems reasonable.
>
> >
> > >
> > > Is runtime suspended state the same as system suspended state here
> > > though? The commit text seems to imply that only clks are disabled when
> > > it's desirable to disable the entire controller. I'm still fuzzy on how
> > > runtime PM and system PM interact because it seems to have changed since
> > > I looked last a few years ago. If the driver can stay in a runtime
> > > suspended state across system suspend then I'm all for it. That would
> > > save time for system PM transitions.
> >
> > In most cases this should be possible. And so far, for this case, I
> > haven't found a good reason to why it shouldn't work.
> >
> > Although, perhaps we need to improve some of the sdhci's library
> > functions for PM, to better support this.
> >
>
> So does that mean it's all just working then? Nothing to do here except
> make wakeup irqs for CD work?
Well, if it "works " or not, I am not really sure.
My point is, I think most of the things that need to be managed at
system suspend/resume are the same things that need to be managed
during runtime suspend/resume (except wakeups). So, rather than
implementing a whole bunch of system suspend/resume specific things,
why not make use of the runtime suspend/resume callbacks instead.
Kind regards
Uffe
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-04-20 9:29 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-20 6:45 [PATCH V4] mmc: sdhci-msm: Update system suspend/resume callbacks of sdhci-msm platform driver Shaik Sajida Bhanu
2020-02-27 14:30 ` Veerabhadrarao Badiganti
2020-03-04 15:34 ` Ulf Hansson
[not found] ` <158334039680.7173.16159724456027777605@swboyd.mtv.corp.google.com>
2020-03-05 13:56 ` Veerabhadrarao Badiganti
2020-03-06 10:07 ` Ulf Hansson
[not found] ` <158463974696.152100.8345578995373250448@swboyd.mtv.corp.google.com>
2020-03-20 10:22 ` Ulf Hansson
[not found] ` <158690616084.105027.4255268086188981149@swboyd.mtv.corp.google.com>
2020-04-20 9:29 ` Ulf Hansson
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