* [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error @ 2020-05-21 3:13 Dinghao Liu 2020-05-21 15:16 ` Bjorn Helgaas 2020-05-29 10:27 ` Lorenzo Pieralisi 0 siblings, 2 replies; 6+ messages in thread From: Dinghao Liu @ 2020-05-21 3:13 UTC (permalink / raw) To: dinghao.liu, kjlu Cc: Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Thierry Reding, Jonathan Hunter, Vidya Sagar, Andrew Murray, linux-pci, linux-tegra, linux-kernel pm_runtime_get_sync() increments the runtime PM usage counter even when it returns an error code. Thus a pairing decrement is needed on the error handling path to keep the counter balanced. Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> --- drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index ae30a2fd3716..2c0d2ce16b47 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -1623,7 +1623,7 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) ret = pinctrl_pm_select_default_state(dev); if (ret < 0) { dev_err(dev, "Failed to configure sideband pins: %d\n", ret); - goto fail_pinctrl; + goto fail_pm_get_sync; } tegra_pcie_init_controller(pcie); @@ -1650,9 +1650,8 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) fail_host_init: tegra_pcie_deinit_controller(pcie); -fail_pinctrl: - pm_runtime_put_sync(dev); fail_pm_get_sync: + pm_runtime_put_sync(dev); pm_runtime_disable(dev); return ret; } -- 2.17.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error 2020-05-21 3:13 [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error Dinghao Liu @ 2020-05-21 15:16 ` Bjorn Helgaas 2020-05-21 15:25 ` Rafael J. Wysocki 2020-05-22 4:36 ` dinghao.liu 2020-05-29 10:27 ` Lorenzo Pieralisi 1 sibling, 2 replies; 6+ messages in thread From: Bjorn Helgaas @ 2020-05-21 15:16 UTC (permalink / raw) To: Dinghao Liu Cc: kjlu, Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Thierry Reding, Jonathan Hunter, Vidya Sagar, Andrew Murray, linux-pci, linux-tegra, linux-kernel, Rafael J. Wysocki, linux-pm [+cc Rafael, linux-pm] On Thu, May 21, 2020 at 11:13:49AM +0800, Dinghao Liu wrote: > pm_runtime_get_sync() increments the runtime PM usage counter even > when it returns an error code. Thus a pairing decrement is needed on > the error handling path to keep the counter balanced. I didn't realize there were so many drivers with the exact same issue. Can we just squash these all into a single patch so we can see them all together? Hmm. There are over 1300 callers of pm_runtime_get_sync(), and it looks like many of them have similar issues, i.e., they have a pattern like this ret = pm_runtime_get_sync(dev); if (ret < 0) return; pm_runtime_put(dev); where there is not a pm_runtime_put() to match every pm_runtime_get_sync(). Random sample: nds32_pmu_reserve_hardware sata_rcar_probe exynos_trng_probe ks_sa_rng_probe omap_aes_probe sun8i_ss_probe omap_aes_probe zynq_gpio_probe amdgpu_hwmon_show_power_avg mtk_crtc_ddp_hw_init ... Surely I'm missing something and these aren't all broken, right? Maybe we could put together a coccinelle script to scan the tree for this issue? > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > --- > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c > index ae30a2fd3716..2c0d2ce16b47 100644 > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > @@ -1623,7 +1623,7 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > ret = pinctrl_pm_select_default_state(dev); > if (ret < 0) { > dev_err(dev, "Failed to configure sideband pins: %d\n", ret); > - goto fail_pinctrl; > + goto fail_pm_get_sync; > } > > tegra_pcie_init_controller(pcie); > @@ -1650,9 +1650,8 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > fail_host_init: > tegra_pcie_deinit_controller(pcie); > -fail_pinctrl: > - pm_runtime_put_sync(dev); > fail_pm_get_sync: > + pm_runtime_put_sync(dev); > pm_runtime_disable(dev); > return ret; > } > -- > 2.17.1 > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error 2020-05-21 15:16 ` Bjorn Helgaas @ 2020-05-21 15:25 ` Rafael J. Wysocki 2020-05-22 6:06 ` dinghao.liu 2020-05-22 4:36 ` dinghao.liu 1 sibling, 1 reply; 6+ messages in thread From: Rafael J. Wysocki @ 2020-05-21 15:25 UTC (permalink / raw) To: Bjorn Helgaas, Dinghao Liu Cc: Kangjie Lu, Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Thierry Reding, Jonathan Hunter, Vidya Sagar, Andrew Murray, Linux PCI, linux-tegra, Linux Kernel Mailing List, Rafael J. Wysocki, Linux PM On Thu, May 21, 2020 at 5:16 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > [+cc Rafael, linux-pm] > > On Thu, May 21, 2020 at 11:13:49AM +0800, Dinghao Liu wrote: > > pm_runtime_get_sync() increments the runtime PM usage counter even > > when it returns an error code. Thus a pairing decrement is needed on > > the error handling path to keep the counter balanced. > > I didn't realize there were so many drivers with the exact same issue. > Can we just squash these all into a single patch so we can see them > all together? > > Hmm. There are over 1300 callers of pm_runtime_get_sync(), and it > looks like many of them have similar issues, i.e., they have a pattern > like this > > ret = pm_runtime_get_sync(dev); > if (ret < 0) > return; > > pm_runtime_put(dev); > > where there is not a pm_runtime_put() to match every > pm_runtime_get_sync(). Random sample: > > nds32_pmu_reserve_hardware > sata_rcar_probe > exynos_trng_probe > ks_sa_rng_probe > omap_aes_probe > sun8i_ss_probe > omap_aes_probe > zynq_gpio_probe > amdgpu_hwmon_show_power_avg > mtk_crtc_ddp_hw_init > ... > > Surely I'm missing something and these aren't all broken, right? If they do what you've said, they are all broken I'm afraid. They should all be doing something like ret = pm_runtime_get_sync(dev); if (ret < 0) goto out; ... out: pm_runtime_put(dev); > Maybe we could put together a coccinelle script to scan the tree for > this issue? > > > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > > --- > > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c > > index ae30a2fd3716..2c0d2ce16b47 100644 > > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > > @@ -1623,7 +1623,7 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > ret = pinctrl_pm_select_default_state(dev); > > if (ret < 0) { > > dev_err(dev, "Failed to configure sideband pins: %d\n", ret); > > - goto fail_pinctrl; > > + goto fail_pm_get_sync; > > } > > > > tegra_pcie_init_controller(pcie); > > @@ -1650,9 +1650,8 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > > > fail_host_init: > > tegra_pcie_deinit_controller(pcie); > > -fail_pinctrl: > > - pm_runtime_put_sync(dev); > > fail_pm_get_sync: > > + pm_runtime_put_sync(dev); Why not pm_runtime_put()? > > pm_runtime_disable(dev); > > return ret; > > } > > -- > > 2.17.1 > > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Re: [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error 2020-05-21 15:25 ` Rafael J. Wysocki @ 2020-05-22 6:06 ` dinghao.liu 0 siblings, 0 replies; 6+ messages in thread From: dinghao.liu @ 2020-05-22 6:06 UTC (permalink / raw) To: Rafael J. Wysocki Cc: Bjorn Helgaas, Kangjie Lu, Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Thierry Reding, Jonathan Hunter, Vidya Sagar, Andrew Murray, Linux PCI, linux-tegra, Linux Kernel Mailing List, Rafael J. Wysocki, Linux PM > On Thu, May 21, 2020 at 5:16 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > > [+cc Rafael, linux-pm] > > > > On Thu, May 21, 2020 at 11:13:49AM +0800, Dinghao Liu wrote: > > > pm_runtime_get_sync() increments the runtime PM usage counter even > > > when it returns an error code. Thus a pairing decrement is needed on > > > the error handling path to keep the counter balanced. > > > > I didn't realize there were so many drivers with the exact same issue. > > Can we just squash these all into a single patch so we can see them > > all together? > > > > Hmm. There are over 1300 callers of pm_runtime_get_sync(), and it > > looks like many of them have similar issues, i.e., they have a pattern > > like this > > > > ret = pm_runtime_get_sync(dev); > > if (ret < 0) > > return; > > > > pm_runtime_put(dev); > > > > where there is not a pm_runtime_put() to match every > > pm_runtime_get_sync(). Random sample: > > > > nds32_pmu_reserve_hardware > > sata_rcar_probe > > exynos_trng_probe > > ks_sa_rng_probe > > omap_aes_probe > > sun8i_ss_probe > > omap_aes_probe > > zynq_gpio_probe > > amdgpu_hwmon_show_power_avg > > mtk_crtc_ddp_hw_init > > ... > > > > Surely I'm missing something and these aren't all broken, right? > > If they do what you've said, they are all broken I'm afraid. > > They should all be doing something like > > ret = pm_runtime_get_sync(dev); > if (ret < 0) > goto out; > > ... > > out: > pm_runtime_put(dev); > > > Maybe we could put together a coccinelle script to scan the tree for > > this issue? > > > > > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > > > --- > > > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c > > > index ae30a2fd3716..2c0d2ce16b47 100644 > > > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > > > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > > > @@ -1623,7 +1623,7 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > > ret = pinctrl_pm_select_default_state(dev); > > > if (ret < 0) { > > > dev_err(dev, "Failed to configure sideband pins: %d\n", ret); > > > - goto fail_pinctrl; > > > + goto fail_pm_get_sync; > > > } > > > > > > tegra_pcie_init_controller(pcie); > > > @@ -1650,9 +1650,8 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > > > > > fail_host_init: > > > tegra_pcie_deinit_controller(pcie); > > > -fail_pinctrl: > > > - pm_runtime_put_sync(dev); > > > fail_pm_get_sync: > > > + pm_runtime_put_sync(dev); > > Why not pm_runtime_put()?\x10 Good question. For functions with PM decrement API somewhere, I will adopt it. If this API is not suitable here, please tell me. > > > > pm_runtime_disable(dev); > > > return ret; > > > } > > > -- > > > 2.17.1 > > > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Re: [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error 2020-05-21 15:16 ` Bjorn Helgaas 2020-05-21 15:25 ` Rafael J. Wysocki @ 2020-05-22 4:36 ` dinghao.liu 1 sibling, 0 replies; 6+ messages in thread From: dinghao.liu @ 2020-05-22 4:36 UTC (permalink / raw) To: Bjorn Helgaas Cc: kjlu, Lorenzo Pieralisi, Rob Herring, Bjorn Helgaas, Thierry Reding, Jonathan Hunter, Vidya Sagar, Andrew Murray, linux-pci, linux-tegra, linux-kernel, Rafael J. Wysocki, linux-pm Hi Bjorn, In fact, most usage of pm_runtime_get_sync() is correct. I made a static analysis tool to check this imbalance in kernel and found about 80 bugs in dirvers. Some of my patches have been accepted and I'm trying to patch the rest as soon as possible. Regards, Dinghao > [+cc Rafael, linux-pm] > > On Thu, May 21, 2020 at 11:13:49AM +0800, Dinghao Liu wrote: > > pm_runtime_get_sync() increments the runtime PM usage counter even > > when it returns an error code. Thus a pairing decrement is needed on > > the error handling path to keep the counter balanced. > > I didn't realize there were so many drivers with the exact same issue. > Can we just squash these all into a single patch so we can see them > all together? > > Hmm. There are over 1300 callers of pm_runtime_get_sync(), and it > looks like many of them have similar issues, i.e., they have a pattern > like this > > ret = pm_runtime_get_sync(dev); > if (ret < 0) > return; > > pm_runtime_put(dev); > > where there is not a pm_runtime_put() to match every > pm_runtime_get_sync(). Random sample: > > nds32_pmu_reserve_hardware > sata_rcar_probe > exynos_trng_probe > ks_sa_rng_probe > omap_aes_probe > sun8i_ss_probe > omap_aes_probe > zynq_gpio_probe > amdgpu_hwmon_show_power_avg > mtk_crtc_ddp_hw_init > ... > > Surely I'm missing something and these aren't all broken, right? > > Maybe we could put together a coccinelle script to scan the tree for > this issue? > > > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > > --- > > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c > > index ae30a2fd3716..2c0d2ce16b47 100644 > > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > > @@ -1623,7 +1623,7 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > ret = pinctrl_pm_select_default_state(dev); > > if (ret < 0) { > > dev_err(dev, "Failed to configure sideband pins: %d\n", ret); > > - goto fail_pinctrl; > > + goto fail_pm_get_sync; > > } > > > > tegra_pcie_init_controller(pcie); > > @@ -1650,9 +1650,8 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > > > fail_host_init: > > tegra_pcie_deinit_controller(pcie); > > -fail_pinctrl: > > - pm_runtime_put_sync(dev); > > fail_pm_get_sync: > > + pm_runtime_put_sync(dev); > > pm_runtime_disable(dev); > > return ret; > > } > > -- > > 2.17.1 > > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error 2020-05-21 3:13 [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error Dinghao Liu 2020-05-21 15:16 ` Bjorn Helgaas @ 2020-05-29 10:27 ` Lorenzo Pieralisi 1 sibling, 0 replies; 6+ messages in thread From: Lorenzo Pieralisi @ 2020-05-29 10:27 UTC (permalink / raw) To: Dinghao Liu Cc: kjlu, Rob Herring, Bjorn Helgaas, Thierry Reding, Jonathan Hunter, Vidya Sagar, Andrew Murray, linux-pci, linux-tegra, linux-kernel On Thu, May 21, 2020 at 11:13:49AM +0800, Dinghao Liu wrote: > pm_runtime_get_sync() increments the runtime PM usage counter even > when it returns an error code. Thus a pairing decrement is needed on > the error handling path to keep the counter balanced. > > Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> > --- > drivers/pci/controller/dwc/pcie-tegra194.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) Applied to pci/tegra, thanks. Lorenzo > diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c > index ae30a2fd3716..2c0d2ce16b47 100644 > --- a/drivers/pci/controller/dwc/pcie-tegra194.c > +++ b/drivers/pci/controller/dwc/pcie-tegra194.c > @@ -1623,7 +1623,7 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > ret = pinctrl_pm_select_default_state(dev); > if (ret < 0) { > dev_err(dev, "Failed to configure sideband pins: %d\n", ret); > - goto fail_pinctrl; > + goto fail_pm_get_sync; > } > > tegra_pcie_init_controller(pcie); > @@ -1650,9 +1650,8 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie) > > fail_host_init: > tegra_pcie_deinit_controller(pcie); > -fail_pinctrl: > - pm_runtime_put_sync(dev); > fail_pm_get_sync: > + pm_runtime_put_sync(dev); > pm_runtime_disable(dev); > return ret; > } > -- > 2.17.1 > ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-05-29 10:27 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-05-21 3:13 [PATCH] [v2] PCI: tegra194: Fix runtime PM imbalance on error Dinghao Liu 2020-05-21 15:16 ` Bjorn Helgaas 2020-05-21 15:25 ` Rafael J. Wysocki 2020-05-22 6:06 ` dinghao.liu 2020-05-22 4:36 ` dinghao.liu 2020-05-29 10:27 ` Lorenzo Pieralisi
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