Hi,
On 7/3/2017 4:55 PM, Manu Gautam wrote:
> Driver currently resumes and increments pm usage_count
> of its child device (dwc3 main) from its runtime_resume
> handler. This requires dwc3 runtime_resume to perform
> pm_runtime_put to decrement the pm usage_count. However
> runtime_put from dwc3 happens for non pci drivers
> (e.g. dwc3-if-simple.c) as well which results in dwc3
> pm usage_count becoming negative after couple of
> runtime suspend resume iterations. Fix this by
> performing runtime_get/put from dwc3-pci driver only
> using workqueue.
Felipe, I don't have any platform that uses dwc3-pci, hence couldn't
test. However, with this change I don't see issue of pm usage_count
becoming -ve on my platform that uses dwc3-of-simple.c.
Let me know if this looks fine.
>
> Signed-off-by: Manu Gautam <mgau...@codeaurora.org>
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index fc556a4..87dedb9 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1378,7 +1378,6 @@ static int dwc3_runtime_resume(struct device *dev)
> }
>
> pm_runtime_mark_last_busy(dev);
> - pm_runtime_put(dev);
>
> return 0;
> }
> diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c
> index 84a2ceb..e354acc 100644
> --- a/drivers/usb/dwc3/dwc3-pci.c
> +++ b/drivers/usb/dwc3/dwc3-pci.c
> @@ -20,6 +20,7 @@
> #include <linux/module.h>
> #include <linux/slab.h>
> #include <linux/pci.h>
> +#include <linux/workqueue.h>
> #include <linux/pm_runtime.h>
> #include <linux/platform_device.h>
> #include <linux/gpio/consumer.h>
> @@ -61,6 +62,7 @@ struct dwc3_pci {
> u8 uuid[16];
>
> unsigned int has_dsm_for_pm:1;
> + struct work_struct wakeup_work;
> };
>
> static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
> @@ -174,6 +176,22 @@ static int dwc3_pci_quirks(struct dwc3_pci *dwc)
> return 0;
> }
>
> +#ifdef CONFIG_PM
> +static void dwc3_pci_resume_work(struct work_struct *work)
> +{
> + struct dwc3_pci *dwc = container_of(work, struct dwc3_pci, wakeup_work);
> + struct platform_device *dwc3 = dwc->dwc3;
> + int ret;
> +
> + ret = pm_runtime_get_sync(&dwc3->dev);
> + if (ret)
> + return;
> +
> + pm_runtime_mark_last_busy(&dwc3->dev);
> + pm_runtime_put_sync_autosuspend(&dwc3->dev);
> +}
> +#endif
> +
> static int dwc3_pci_probe(struct pci_dev *pci,
> const struct pci_device_id *id)
> {
> @@ -233,6 +251,9 @@ static int dwc3_pci_probe(struct pci_dev *pci,
> device_set_run_wake(dev, true);
> pci_set_drvdata(pci, dwc);
> pm_runtime_put(dev);
> +#ifdef CONFIG_PM
> + INIT_WORK(&dwc->wakeup_work, dwc3_pci_resume_work);
> +#endif
>
> return 0;
> err:
> @@ -244,6 +265,9 @@ static void dwc3_pci_remove(struct pci_dev *pci)
> {
> struct dwc3_pci *dwc = pci_get_drvdata(pci);
>
> +#ifdef CONFIG_PM
> + cancel_work_sync(&dwc->wakeup_work);
> +#endif
> device_init_wakeup(&pci->dev, false);
> pm_runtime_get(&pci->dev);
> platform_device_unregister(dwc->dwc3);
> @@ -319,14 +343,15 @@ static int dwc3_pci_runtime_suspend(struct device *dev)
> static int dwc3_pci_runtime_resume(struct device *dev)
> {
> struct dwc3_pci *dwc = dev_get_drvdata(dev);
> - struct platform_device *dwc3 = dwc->dwc3;
> int ret;
>
> ret = dwc3_pci_dsm(dwc, PCI_INTEL_BXT_STATE_D0);
> if (ret)
> return ret;
>
> - return pm_runtime_get(&dwc3->dev);
> + queue_work(pm_wq, &dwc->wakeup_work);
> +
> + return 0;
> }
> #endif /* CONFIG_PM */
>
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