Re: [Freedreno] [Patch v15 2/5] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device
On Thu, Aug 30, 2018 at 3:04 PM Tomasz Figa wrote: > > On Thu, Aug 30, 2018 at 6:22 PM Vivek Gautam > wrote: > > > > On Mon, Aug 27, 2018 at 4:27 PM Vivek Gautam > > wrote: > > > > > > From: Sricharan R > > > > > > The smmu device probe/remove and add/remove master device callbacks > > > gets called when the smmu is not linked to its master, that is without > > > the context of the master device. So calling runtime apis in those places > > > separately. > > > > > > Signed-off-by: Sricharan R > > > [vivek: Cleanup pm runtime calls] > > > Signed-off-by: Vivek Gautam > > > Reviewed-by: Tomasz Figa > > > Tested-by: Srinivas Kandagatla > > > --- > > > > > > Changes since v14: > > > - none. > > > > > > drivers/iommu/arm-smmu.c | 101 > > > +++ > > > 1 file changed, 93 insertions(+), 8 deletions(-) > > > > > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > > > index a81224bc6637..23b4a60149b6 100644 > > > --- a/drivers/iommu/arm-smmu.c > > > +++ b/drivers/iommu/arm-smmu.c > > > > [snip] > > > > > @@ -2131,6 +2188,26 @@ static int arm_smmu_device_probe(struct > > > platform_device *pdev) > > > if (err) > > > return err; > > > > > > + /* > > > +* We want to avoid touching dev->power.lock in fastpaths unless > > > +* it's really going to do something useful - pm_runtime_enabled() > > > +* can serve as an ideal proxy for that decision. So, > > > conditionally > > > +* enable pm_runtime. > > > +*/ > > > + if (dev->pm_domain) > > > + pm_runtime_enable(dev); > > > + > > > + err = arm_smmu_rpm_get(smmu); > > > > We shouldn't be doing a runtime_get() yet, as this eventually calls > > arm_smmu_device_reset(). > > arm_smmu_device_reset() should be called only after > > arm_smmu_device_cfg_probe(). > > So, I plan to replace the pm_runtime_get/put() calls in probe() with > > simple clk_bulk_enable() > > to let the driver initialize smmu, and at the end of the probe we can > > disable the clocks and > > enable runtime pm over the device to let it take care of the device > > further-on. > > > > We can avoid the explicit clock disable by just calling > pm_runtime_set_active() before pm_runtime_enable(), assuming that what > probe does is symmetrical with the suspend callback, which would be > called after the latter. Sure, that sounds reasonable. Will use pm_runtime_set_active() instead of explicitly disabling the clocks.Thanks. Best regards Vivek > > Best regards, > Tomasz > ___ > iommu mailing list > io...@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation ___ Freedreno mailing list Freedreno@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/freedreno
Re: [Freedreno] [Patch v15 2/5] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device
On Thu, Aug 30, 2018 at 6:22 PM Vivek Gautam wrote: > > On Mon, Aug 27, 2018 at 4:27 PM Vivek Gautam > wrote: > > > > From: Sricharan R > > > > The smmu device probe/remove and add/remove master device callbacks > > gets called when the smmu is not linked to its master, that is without > > the context of the master device. So calling runtime apis in those places > > separately. > > > > Signed-off-by: Sricharan R > > [vivek: Cleanup pm runtime calls] > > Signed-off-by: Vivek Gautam > > Reviewed-by: Tomasz Figa > > Tested-by: Srinivas Kandagatla > > --- > > > > Changes since v14: > > - none. > > > > drivers/iommu/arm-smmu.c | 101 > > +++ > > 1 file changed, 93 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > > index a81224bc6637..23b4a60149b6 100644 > > --- a/drivers/iommu/arm-smmu.c > > +++ b/drivers/iommu/arm-smmu.c > > [snip] > > > @@ -2131,6 +2188,26 @@ static int arm_smmu_device_probe(struct > > platform_device *pdev) > > if (err) > > return err; > > > > + /* > > +* We want to avoid touching dev->power.lock in fastpaths unless > > +* it's really going to do something useful - pm_runtime_enabled() > > +* can serve as an ideal proxy for that decision. So, conditionally > > +* enable pm_runtime. > > +*/ > > + if (dev->pm_domain) > > + pm_runtime_enable(dev); > > + > > + err = arm_smmu_rpm_get(smmu); > > We shouldn't be doing a runtime_get() yet, as this eventually calls > arm_smmu_device_reset(). > arm_smmu_device_reset() should be called only after > arm_smmu_device_cfg_probe(). > So, I plan to replace the pm_runtime_get/put() calls in probe() with > simple clk_bulk_enable() > to let the driver initialize smmu, and at the end of the probe we can > disable the clocks and > enable runtime pm over the device to let it take care of the device > further-on. > We can avoid the explicit clock disable by just calling pm_runtime_set_active() before pm_runtime_enable(), assuming that what probe does is symmetrical with the suspend callback, which would be called after the latter. Best regards, Tomasz ___ Freedreno mailing list Freedreno@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/freedreno
Re: [Freedreno] [Patch v15 2/5] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device
On Mon, Aug 27, 2018 at 4:27 PM Vivek Gautam
wrote:
>
> From: Sricharan R
>
> The smmu device probe/remove and add/remove master device callbacks
> gets called when the smmu is not linked to its master, that is without
> the context of the master device. So calling runtime apis in those places
> separately.
>
> Signed-off-by: Sricharan R
> [vivek: Cleanup pm runtime calls]
> Signed-off-by: Vivek Gautam
> Reviewed-by: Tomasz Figa
> Tested-by: Srinivas Kandagatla
> ---
>
> Changes since v14:
> - none.
>
> drivers/iommu/arm-smmu.c | 101
> +++
> 1 file changed, 93 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index a81224bc6637..23b4a60149b6 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
[snip]
> @@ -2131,6 +2188,26 @@ static int arm_smmu_device_probe(struct
> platform_device *pdev)
> if (err)
> return err;
>
> + /*
> +* We want to avoid touching dev->power.lock in fastpaths unless
> +* it's really going to do something useful - pm_runtime_enabled()
> +* can serve as an ideal proxy for that decision. So, conditionally
> +* enable pm_runtime.
> +*/
> + if (dev->pm_domain)
> + pm_runtime_enable(dev);
> +
> + err = arm_smmu_rpm_get(smmu);
We shouldn't be doing a runtime_get() yet, as this eventually calls
arm_smmu_device_reset().
arm_smmu_device_reset() should be called only after arm_smmu_device_cfg_probe().
So, I plan to replace the pm_runtime_get/put() calls in probe() with
simple clk_bulk_enable()
to let the driver initialize smmu, and at the end of the probe we can
disable the clocks and
enable runtime pm over the device to let it take care of the device further-on.
> + if (err < 0)
> + return err;
> +
> + /* Enable clocks explicitly if runtime PM is disabled */
> + if (!pm_runtime_enabled(dev)) {
> + err = clk_bulk_enable(smmu->num_clks, smmu->clks);
> + if (err)
> + return err;
> + }
> +
> err = arm_smmu_device_cfg_probe(smmu);
> if (err)
> return err;
[snip]
Best regards
Vivek
--
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of Code Aurora Forum, hosted by The Linux Foundation
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