drivers/pmdomain/imx/imx8m-blk-ctrl.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
From: Vitor Soares <vitor.soares@toradex.com>
During the probe, the genpd power_dev is added to the dpm_list after
blk_ctrl due to its parent/child relationship. Making the blk_ctrl
suspend after and resume before the genpd power_dev.
As a consequence, the system hangs when resuming the VPU due to the
power domain dependency.
To ensure the proper suspend/resume order, add a device link betweem
blk_ctrl and genpd power_dev. It guarantees genpd power_dev is suspended
after and resumed before blk-ctrl.
Cc: <stable@vger.kernel.org>
Closes: https://lore.kernel.org/all/fccbb040330a706a4f7b34875db1d896a0bf81c8.camel@gmail.com/
Link: https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
Fixes: 2684ac05a8c4 ("soc: imx: add i.MX8M blk-ctrl driver")
Suggested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
---
This is a new patch, but is a follow-up of:
https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
As suggested by Lucas, we are addressing this PM issue in the imx8m-blk-ctrl
driver instead of in the imx8mm.dtsi.
drivers/pmdomain/imx/imx8m-blk-ctrl.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
index ca942d7929c2..cd0d2296080d 100644
--- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
+++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
@@ -283,6 +283,20 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
goto cleanup_pds;
}
+ /*
+ * Enforce suspend/resume ordering by making genpd power_dev a
+ * provider of blk-ctrl. Genpd power_dev is suspended after and
+ * resumed before blk-ctrl.
+ */
+ if (!device_link_add(dev, domain->power_dev, DL_FLAG_STATELESS)) {
+ ret = -EINVAL;
+ dev_err_probe(dev, ret,
+ "failed to link to %s\n", data->name);
+ pm_genpd_remove(&domain->genpd);
+ dev_pm_domain_detach(domain->power_dev, true);
+ goto cleanup_pds;
+ }
+
/*
* We use runtime PM to trigger power on/off of the upstream GPC
* domain, as a strict hierarchical parent/child power domain
@@ -324,6 +338,7 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
of_genpd_del_provider(dev->of_node);
cleanup_pds:
for (i--; i >= 0; i--) {
+ device_link_remove(dev, bc->domains[i].power_dev);
pm_genpd_remove(&bc->domains[i].genpd);
dev_pm_domain_detach(bc->domains[i].power_dev, true);
}
@@ -343,6 +358,7 @@ static void imx8m_blk_ctrl_remove(struct platform_device *pdev)
for (i = 0; bc->onecell_data.num_domains; i++) {
struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
+ device_link_remove(&pdev->dev, domain->power_dev);
pm_genpd_remove(&domain->genpd);
dev_pm_domain_detach(domain->power_dev, true);
}
--
2.34.1On Thu, 18 Apr 2024 at 17:52, Vitor Soares <ivitro@gmail.com> wrote:
>
> From: Vitor Soares <vitor.soares@toradex.com>
>
> During the probe, the genpd power_dev is added to the dpm_list after
> blk_ctrl due to its parent/child relationship. Making the blk_ctrl
> suspend after and resume before the genpd power_dev.
>
> As a consequence, the system hangs when resuming the VPU due to the
> power domain dependency.
>
> To ensure the proper suspend/resume order, add a device link betweem
> blk_ctrl and genpd power_dev. It guarantees genpd power_dev is suspended
> after and resumed before blk-ctrl.
Before discussing $subject patch, would you mind explaining to me why
imx8m-blk-ctrl needs to use the ->suspend() callback at all?
Looking closer at that code (imx8m_blk_ctrl_suspend()), it calls
pm_runtime_get_sync() for devices to power on "everything". Why isn't
that managed by the consumer drivers (on a case by case basis) that
are managing the devices that are attached to the genpds instead?
Kind regards
Uffe
>
> Cc: <stable@vger.kernel.org>
> Closes: https://lore.kernel.org/all/fccbb040330a706a4f7b34875db1d896a0bf81c8.camel@gmail.com/
> Link: https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
> Fixes: 2684ac05a8c4 ("soc: imx: add i.MX8M blk-ctrl driver")
> Suggested-by: Lucas Stach <l.stach@pengutronix.de>
> Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
> ---
>
> This is a new patch, but is a follow-up of:
> https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
>
> As suggested by Lucas, we are addressing this PM issue in the imx8m-blk-ctrl
> driver instead of in the imx8mm.dtsi.
>
> drivers/pmdomain/imx/imx8m-blk-ctrl.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> index ca942d7929c2..cd0d2296080d 100644
> --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> @@ -283,6 +283,20 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
> goto cleanup_pds;
> }
>
> + /*
> + * Enforce suspend/resume ordering by making genpd power_dev a
> + * provider of blk-ctrl. Genpd power_dev is suspended after and
> + * resumed before blk-ctrl.
> + */
> + if (!device_link_add(dev, domain->power_dev, DL_FLAG_STATELESS)) {
> + ret = -EINVAL;
> + dev_err_probe(dev, ret,
> + "failed to link to %s\n", data->name);
> + pm_genpd_remove(&domain->genpd);
> + dev_pm_domain_detach(domain->power_dev, true);
> + goto cleanup_pds;
> + }
> +
> /*
> * We use runtime PM to trigger power on/off of the upstream GPC
> * domain, as a strict hierarchical parent/child power domain
> @@ -324,6 +338,7 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
> of_genpd_del_provider(dev->of_node);
> cleanup_pds:
> for (i--; i >= 0; i--) {
> + device_link_remove(dev, bc->domains[i].power_dev);
> pm_genpd_remove(&bc->domains[i].genpd);
> dev_pm_domain_detach(bc->domains[i].power_dev, true);
> }
> @@ -343,6 +358,7 @@ static void imx8m_blk_ctrl_remove(struct platform_device *pdev)
> for (i = 0; bc->onecell_data.num_domains; i++) {
> struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
>
> + device_link_remove(&pdev->dev, domain->power_dev);
> pm_genpd_remove(&domain->genpd);
> dev_pm_domain_detach(domain->power_dev, true);
> }
> --
> 2.34.1
>
On Fri, 2024-05-10 at 11:34 +0200, Ulf Hansson wrote:
> On Thu, 18 Apr 2024 at 17:52, Vitor Soares <ivitro@gmail.com> wrote:
> >
> > From: Vitor Soares <vitor.soares@toradex.com>
> >
> > During the probe, the genpd power_dev is added to the dpm_list after
> > blk_ctrl due to its parent/child relationship. Making the blk_ctrl
> > suspend after and resume before the genpd power_dev.
> >
> > As a consequence, the system hangs when resuming the VPU due to the
> > power domain dependency.
> >
> > To ensure the proper suspend/resume order, add a device link betweem
> > blk_ctrl and genpd power_dev. It guarantees genpd power_dev is suspended
> > after and resumed before blk-ctrl.
>
> Before discussing $subject patch, would you mind explaining to me why
> imx8m-blk-ctrl needs to use the ->suspend() callback at all?
>
> Looking closer at that code (imx8m_blk_ctrl_suspend()), it calls
> pm_runtime_get_sync() for devices to power on "everything". Why isn't
> that managed by the consumer drivers (on a case by case basis) that
> are managing the devices that are attached to the genpds instead?
>
> Kind regards
> Uffe
>
Hi Lucas, you know the driver architecture better than I do. Would you mind
addressing Ulf concerns?
In addition to that, I would say that given that this is a bug fix, it would be
nice to have it merged. Having a buggy driver in the kernel is not solving this
kind of architectural question.
Best regards,
Vitor Soares
> >
> > Cc: <stable@vger.kernel.org>
> > Closes:
> > https://lore.kernel.org/all/fccbb040330a706a4f7b34875db1d896a0bf81c8.camel@gmail.com/
> > Link: https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
> > Fixes: 2684ac05a8c4 ("soc: imx: add i.MX8M blk-ctrl driver")
> > Suggested-by: Lucas Stach <l.stach@pengutronix.de>
> > Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
> > ---
> >
> > This is a new patch, but is a follow-up of:
> > https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
> >
> > As suggested by Lucas, we are addressing this PM issue in the imx8m-blk-ctrl
> > driver instead of in the imx8mm.dtsi.
> >
> > drivers/pmdomain/imx/imx8m-blk-ctrl.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> > b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> > index ca942d7929c2..cd0d2296080d 100644
> > --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> > +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> > @@ -283,6 +283,20 @@ static int imx8m_blk_ctrl_probe(struct platform_device
> > *pdev)
> > goto cleanup_pds;
> > }
> >
> > + /*
> > + * Enforce suspend/resume ordering by making genpd power_dev
> > a
> > + * provider of blk-ctrl. Genpd power_dev is suspended after
> > and
> > + * resumed before blk-ctrl.
> > + */
> > + if (!device_link_add(dev, domain->power_dev,
> > DL_FLAG_STATELESS)) {
> > + ret = -EINVAL;
> > + dev_err_probe(dev, ret,
> > + "failed to link to %s\n", data->name);
> > + pm_genpd_remove(&domain->genpd);
> > + dev_pm_domain_detach(domain->power_dev, true);
> > + goto cleanup_pds;
> > + }
> > +
> > /*
> > * We use runtime PM to trigger power on/off of the upstream
> > GPC
> > * domain, as a strict hierarchical parent/child power
> > domain
> > @@ -324,6 +338,7 @@ static int imx8m_blk_ctrl_probe(struct platform_device
> > *pdev)
> > of_genpd_del_provider(dev->of_node);
> > cleanup_pds:
> > for (i--; i >= 0; i--) {
> > + device_link_remove(dev, bc->domains[i].power_dev);
> > pm_genpd_remove(&bc->domains[i].genpd);
> > dev_pm_domain_detach(bc->domains[i].power_dev, true);
> > }
> > @@ -343,6 +358,7 @@ static void imx8m_blk_ctrl_remove(struct platform_device
> > *pdev)
> > for (i = 0; bc->onecell_data.num_domains; i++) {
> > struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
> >
> > + device_link_remove(&pdev->dev, domain->power_dev);
> > pm_genpd_remove(&domain->genpd);
> > dev_pm_domain_detach(domain->power_dev, true);
> > }
> > --
> > 2.34.1
> >
Am Donnerstag, dem 18.04.2024 um 16:51 +0100 schrieb Vitor Soares:
> From: Vitor Soares <vitor.soares@toradex.com>
>
> During the probe, the genpd power_dev is added to the dpm_list after
> blk_ctrl due to its parent/child relationship. Making the blk_ctrl
> suspend after and resume before the genpd power_dev.
>
> As a consequence, the system hangs when resuming the VPU due to the
> power domain dependency.
>
> To ensure the proper suspend/resume order, add a device link betweem
> blk_ctrl and genpd power_dev. It guarantees genpd power_dev is suspended
> after and resumed before blk-ctrl.
>
> Cc: <stable@vger.kernel.org>
> Closes: https://lore.kernel.org/all/fccbb040330a706a4f7b34875db1d896a0bf81c8.camel@gmail.com/
> Link: https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
> Fixes: 2684ac05a8c4 ("soc: imx: add i.MX8M blk-ctrl driver")
> Suggested-by: Lucas Stach <l.stach@pengutronix.de>
> Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
> ---
>
> This is a new patch, but is a follow-up of:
> https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
>
> As suggested by Lucas, we are addressing this PM issue in the imx8m-blk-ctrl
> driver instead of in the imx8mm.dtsi.
>
> drivers/pmdomain/imx/imx8m-blk-ctrl.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> index ca942d7929c2..cd0d2296080d 100644
> --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> @@ -283,6 +283,20 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
> goto cleanup_pds;
> }
>
> + /*
> + * Enforce suspend/resume ordering by making genpd power_dev a
> + * provider of blk-ctrl. Genpd power_dev is suspended after and
> + * resumed before blk-ctrl.
> + */
> + if (!device_link_add(dev, domain->power_dev, DL_FLAG_STATELESS)) {
> + ret = -EINVAL;
> + dev_err_probe(dev, ret,
> + "failed to link to %s\n", data->name);
> + pm_genpd_remove(&domain->genpd);
> + dev_pm_domain_detach(domain->power_dev, true);
> + goto cleanup_pds;
> + }
> +
> /*
> * We use runtime PM to trigger power on/off of the upstream GPC
> * domain, as a strict hierarchical parent/child power domain
> @@ -324,6 +338,7 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev)
> of_genpd_del_provider(dev->of_node);
> cleanup_pds:
> for (i--; i >= 0; i--) {
> + device_link_remove(dev, bc->domains[i].power_dev);
> pm_genpd_remove(&bc->domains[i].genpd);
> dev_pm_domain_detach(bc->domains[i].power_dev, true);
> }
> @@ -343,6 +358,7 @@ static void imx8m_blk_ctrl_remove(struct platform_device *pdev)
> for (i = 0; bc->onecell_data.num_domains; i++) {
> struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
>
> + device_link_remove(&pdev->dev, domain->power_dev);
> pm_genpd_remove(&domain->genpd);
> dev_pm_domain_detach(domain->power_dev, true);
> }
On Thu, Apr 18, 2024 at 04:51:51PM +0100, Vitor Soares wrote: > From: Vitor Soares <vitor.soares@toradex.com> > > During the probe, the genpd power_dev is added to the dpm_list after > blk_ctrl due to its parent/child relationship. Making the blk_ctrl > suspend after and resume before the genpd power_dev. > > As a consequence, the system hangs when resuming the VPU due to the > power domain dependency. > > To ensure the proper suspend/resume order, add a device link betweem > blk_ctrl and genpd power_dev. It guarantees genpd power_dev is suspended > after and resumed before blk-ctrl. > Cc: Adam Ford Francesco
On Wed, May 8, 2024 at 12:40 PM Francesco Dolcini <francesco@dolcini.it> wrote: > > On Thu, Apr 18, 2024 at 04:51:51PM +0100, Vitor Soares wrote: > > From: Vitor Soares <vitor.soares@toradex.com> > > > > During the probe, the genpd power_dev is added to the dpm_list after > > blk_ctrl due to its parent/child relationship. Making the blk_ctrl > > suspend after and resume before the genpd power_dev. > > > > As a consequence, the system hangs when resuming the VPU due to the > > power domain dependency. > > > > To ensure the proper suspend/resume order, add a device link betweem > > blk_ctrl and genpd power_dev. It guarantees genpd power_dev is suspended > > after and resumed before blk-ctrl. > > > > Cc: Adam Ford Thanks! This is what I was thinking from the other thread. I just didn't see this one. adam > > Francesco >
> …, add a device link betweem > blk_ctrl and genpd power_dev. … I hope that a typo will be avoided in this change description for the final commit. Regards, Markus
Hi Markus, On Thu, 2024-04-18 at 18:24 +0200, Markus Elfring wrote: > > …, add a device link betweem > > blk_ctrl and genpd power_dev. … > > I hope that a typo will be avoided in this change description for the final commit. > Thanks for you feedback. I will fix it next version. Best regards, Vitor Soares > Regards, > Markus
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