Re: [PATCH V3 4/6] usb: ohci-platform: Add support for Broadcom STB SoC's

[Florian Fainelli <f.fainelli@gmail.com>]

On 11/6/18 1:40 PM, Al Cooper wrote:
> On 11/6/18 11:08 AM, Alan Stern wrote:
>> On Mon, 5 Nov 2018, Al Cooper wrote:
>>
>>> Add support for Broadcom STB SoC's to the ohci platform driver.
>>>
>>> Signed-off-by: Al Cooper <alcooperx@gmail.com>
>>> ---
>>
>>> @@ -177,6 +189,8 @@ static int ohci_platform_probe(struct
>>> platform_device *dev)
>>>           ohci->flags |= OHCI_QUIRK_FRAME_NO;
>>>       if (pdata->num_ports)
>>>           ohci->num_ports = pdata->num_ports;
>>> +    if (pdata->suspend_without_phy_exit)
>>> +        hcd->suspend_without_phy_exit = 1;
>>
>> Sorry if I missed this in the earlier discussions...  Is there any
>> possibility of adding a DT binding that could express this requirement,
>> instead of putting it in the platform data?
>>
>> Alan Stern
>>
> 
> Alan,
> 
> That was my original approach but internal review suggested that I use
> pdata instead. Below is my original patch for:

And the reason for that suggestion was really because it was percevied
as encoding a driver behavior as a Device Tree property as opposed to
describing something that was inherently and strictly a hardware
behavior (therefore suitable for Device Tree).

> [PATCH V3 2/6] usb: core: Add ability to skip phy exit on suspend and
> init on resume
> With this patch I can then use ohci_platform.c without any
> modifications. Could you let me know what you think?
> 
> Thanks
> Al
> 
> Add the ability to skip calling the PHY's exit routine on suspend
> and the PHY's init routine on resume. This is to handle a USB PHY
> that should have it's power_off function called on suspend but cannot
> have it's exit function called because on exit it will disable the
> PHY to the point where register accesses to the Host Controllers
> using the PHY will be disabled and the host drivers will crash.
> 
> This is enabled with the HCD flag "suspend_without_phy_exit" which
> can be set from any HCD driver or from the device-tree property
> "suspend-without-phy-exit".
> 
> Signed-off-by: Al Cooper <alcooperx@gmail.com>
> ---
>  drivers/usb/core/hcd.c  |  8 ++++----
>  drivers/usb/core/phy.c  | 21 +++++++++++++++------
>  drivers/usb/core/phy.h  |  9 ++++++---
>  include/linux/usb/hcd.h |  3 +++
>  4 files changed, 28 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 1c21955fe7c0..e67e4d6b3d21 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2263,7 +2263,7 @@ int hcd_bus_suspend(struct usb_device *rhdev,
> pm_message_t msg)
>          hcd->state = HC_STATE_SUSPENDED;
> 
>          if (!PMSG_IS_AUTO(msg))
> -            usb_phy_roothub_suspend(hcd->self.sysdev,
> +            usb_phy_roothub_suspend(hcd,
>                          hcd->phy_roothub);
> 
>          /* Did we race with a root-hub wakeup event? */
> @@ -2304,7 +2304,7 @@ int hcd_bus_resume(struct usb_device *rhdev,
> pm_message_t msg)
>      }
> 
>      if (!PMSG_IS_AUTO(msg)) {
> -        status = usb_phy_roothub_resume(hcd->self.sysdev,
> +        status = usb_phy_roothub_resume(hcd,
>                          hcd->phy_roothub);
>          if (status)
>              return status;
> @@ -2347,7 +2347,7 @@ int hcd_bus_resume(struct usb_device *rhdev,
> pm_message_t msg)
>          }
>      } else {
>          hcd->state = old_state;
> -        usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
> +        usb_phy_roothub_suspend(hcd, hcd->phy_roothub);
>          dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
>                  "resume", status);
>          if (status != -ESHUTDOWN)
> @@ -2744,7 +2744,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
>      struct usb_device *rhdev;
> 
>      if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
> -        hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
> +        hcd->phy_roothub = usb_phy_roothub_alloc(hcd);
>          if (IS_ERR(hcd->phy_roothub))
>              return PTR_ERR(hcd->phy_roothub);
> 
> diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
> index 9879767452a2..0eb12566f1c3 100644
> --- a/drivers/usb/core/phy.c
> +++ b/drivers/usb/core/phy.c
> @@ -45,10 +45,11 @@ static int usb_phy_roothub_add_phy(struct device
> *dev, int index,
>      return 0;
>  }
> 
> -struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
> +struct usb_phy_roothub *usb_phy_roothub_alloc(struct usb_hcd *hcd)
>  {
>      struct usb_phy_roothub *phy_roothub;
>      int i, num_phys, err;
> +    struct device *dev = hcd->self.sysdev;
> 
>      if (!IS_ENABLED(CONFIG_GENERIC_PHY))
>          return NULL;
> @@ -58,6 +59,9 @@ struct usb_phy_roothub *usb_phy_roothub_alloc(struct
> device *dev)
>      if (num_phys <= 0)
>          return NULL;
> 
> +    if (device_property_read_bool(dev, "suspend-without-phy-exit"))
> +        hcd->suspend_without_phy_exit = 1;
> +
>      phy_roothub = devm_kzalloc(dev, sizeof(*phy_roothub), GFP_KERNEL);
>      if (!phy_roothub)
>          return ERR_PTR(-ENOMEM);
> @@ -161,26 +165,30 @@ void usb_phy_roothub_power_off(struct
> usb_phy_roothub *phy_roothub)
>  }
>  EXPORT_SYMBOL_GPL(usb_phy_roothub_power_off);
> 
> -int usb_phy_roothub_suspend(struct device *controller_dev,
> +int usb_phy_roothub_suspend(struct usb_hcd *hcd,
>                  struct usb_phy_roothub *phy_roothub)
>  {
> +    struct device *controller_dev = hcd->self.sysdev;
> +
>      usb_phy_roothub_power_off(phy_roothub);
> 
>      /* keep the PHYs initialized so the device can wake up the system */
> -    if (device_may_wakeup(controller_dev))
> +    if (device_may_wakeup(controller_dev) ||
> hcd->suspend_without_phy_exit)
>          return 0;
> 
>      return usb_phy_roothub_exit(phy_roothub);
>  }
>  EXPORT_SYMBOL_GPL(usb_phy_roothub_suspend);
> 
> -int usb_phy_roothub_resume(struct device *controller_dev,
> +int usb_phy_roothub_resume(struct usb_hcd *hcd,
>                 struct usb_phy_roothub *phy_roothub)
>  {
> +    struct device *controller_dev = hcd->self.sysdev;
>      int err;
> 
>      /* if the device can't wake up the system _exit was called */
> -    if (!device_may_wakeup(controller_dev)) {
> +    if (!device_may_wakeup(controller_dev) &&
> +        !hcd->suspend_without_phy_exit) {
>          err = usb_phy_roothub_init(phy_roothub);
>          if (err)
>              return err;
> @@ -189,7 +197,8 @@ int usb_phy_roothub_resume(struct device
> *controller_dev,
>      err = usb_phy_roothub_power_on(phy_roothub);
> 
>      /* undo _init if _power_on failed */
> -    if (err && !device_may_wakeup(controller_dev))
> +    if (err && !device_may_wakeup(controller_dev)
> +        && !hcd->suspend_without_phy_exit)
>          usb_phy_roothub_exit(phy_roothub);
> 
>      return err;
> diff --git a/drivers/usb/core/phy.h b/drivers/usb/core/phy.h
> index 88a3c037e9df..34293e11a917 100644
> --- a/drivers/usb/core/phy.h
> +++ b/drivers/usb/core/phy.h
> @@ -5,13 +5,16 @@
>   * Copyright (C) 2018 Martin Blumenstingl
> <martin.blumenstingl@googlemail.com>
>   */
> 
> +#include <linux/usb.h>
> +#include <linux/usb/hcd.h>
> +
>  #ifndef __USB_CORE_PHY_H_
>  #define __USB_CORE_PHY_H_
> 
>  struct device;
>  struct usb_phy_roothub;
> 
> -struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev);
> +struct usb_phy_roothub *usb_phy_roothub_alloc(struct usb_hcd *hcd);
> 
>  int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub);
>  int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub);
> @@ -19,9 +22,9 @@
>  int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub);
>  void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub);
> 
> -int usb_phy_roothub_suspend(struct device *controller_dev,
> +int usb_phy_roothub_suspend(struct usb_hcd *hcd,
>                  struct usb_phy_roothub *phy_roothub);
> -int usb_phy_roothub_resume(struct device *controller_dev,
> +int usb_phy_roothub_resume(struct usb_hcd *hcd,
>                 struct usb_phy_roothub *phy_roothub);
> 
>  #endif /* __USB_CORE_PHY_H_ */
> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
> index 97e2ddec18b1..87a104055b5e 100644
> --- a/include/linux/usb/hcd.h
> +++ b/include/linux/usb/hcd.h
> @@ -157,6 +157,9 @@ struct usb_hcd {
>       */
>      unsigned        skip_phy_initialization:1;
> 
> +    /* Some phys don't want the phy's exit/init called on
> suspend/resume */
> +    unsigned        suspend_without_phy_exit:1;
> +
>      /* The next flag is a stopgap, to be removed when all the HCDs
>       * support the new root-hub polling mechanism. */
>      unsigned        uses_new_polling:1;


-- 
Florian