On Mon, Jun 11, 2012 at 10:24:33AM +0800, Lan Tianyu wrote:
> On our developping machine, bios can provide usb port's power control via
> acpi. This patch is to provide usb port's power control way through setting
> or clearing PORT_POWER feature requests. Add two functions usb_acpi_power_manageable()
> and usb_acpi_set_power_state(). The first one is used to find whether the
> usb port has acpi power resource and the second is to set the power state.
> They are invoked in the xhci_hub_control() where clearing or setting PORT_POWER
> feature requests are processed.
>
> Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
> ---
> drivers/usb/core/usb-acpi.c | 28 ++++++++++++++++++++++++++++
> drivers/usb/host/xhci-hub.c | 10 ++++++++++
> include/linux/usb.h | 10 ++++++++++
> 3 files changed, 48 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
> index 82c90d0..e95f26f 100644
> --- a/drivers/usb/core/usb-acpi.c
> +++ b/drivers/usb/core/usb-acpi.c
> @@ -19,6 +19,34 @@
>
> #include "usb.h"
>
> +bool usb_acpi_power_manageable(struct usb_device *hdev, int port1)
> +{
> + acpi_handle port_handle;
> +
> + port_handle = usb_get_hub_port_acpi_handle(hdev,
> + port1);
> + return port_handle ? acpi_bus_power_manageable(port_handle) : false;
Ick, I _really_ hate the ? : usage in C, please use real if statements
so that everyone can read and understand them easier. You do that a lot
here, please fix them all.
> +}
> +EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
> +
> +int usb_acpi_set_power_state(struct usb_device *hdev, int port1, bool enable)
> +{
> + acpi_handle port_handle;
> + unsigned char state;
> + int error = -EINVAL;
> +
> + port_handle = (acpi_handle)usb_get_hub_port_acpi_handle(hdev,
> + port1);
> + state = enable ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD;
> + error = acpi_bus_set_power(port_handle, state);
You forgot to check port_handle here.
Why not call usb_acpi_power_manageable() to ensure that you can do this?
> + if (!error)
> + dev_dbg(&hdev->dev, "The power of hub port %d was set to %s\n",
> + port1, enable ? "enable" : "disabe");
Why not report the error if debugging as well?
> +
> + return error;
> +}
> +EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
> +
> static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
> acpi_handle handle, int port1)
> {
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index 2c55fcf..0ce48b3 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -728,6 +728,11 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
>
> temp = xhci_readl(xhci, port_array[wIndex]);
> xhci_dbg(xhci, "set port power, actual port %d status = 0x%x\n", wIndex, temp);
> +
> + if (usb_acpi_power_manageable(hcd->self.root_hub,
> + wIndex + 1))
Why +1? If you have to do this everywhere, then do it only in the
function, so you can be 0 based properly.
Also, minor coding style nit, please rewrite as:
if (usb_acpi_power_manageable(hcd->self.root_hub,
wIndex + 1))
Or even better yet, use a temp variable for the value returned and then
check that, it's clearer and easier to read, right?
> + usb_acpi_set_power_state(hcd->self.root_hub,
> + wIndex + 1, true);
Same question about +1 here.
> break;
> case USB_PORT_FEAT_RESET:
> temp = (temp | PORT_RESET);
> @@ -830,6 +835,11 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
> case USB_PORT_FEAT_POWER:
> xhci_writel(xhci, temp & ~PORT_POWER,
> port_array[wIndex]);
> +
> + if (usb_acpi_power_manageable(hcd->self.root_hub,
> + wIndex + 1))
> + usb_acpi_set_power_state(hcd->self.root_hub,
> + wIndex + 1, false);
> break;
> default:
> goto error;
> diff --git a/include/linux/usb.h b/include/linux/usb.h
> index feb0a04..92f8898 100644
> --- a/include/linux/usb.h
> +++ b/include/linux/usb.h
> @@ -599,6 +599,16 @@ extern int usb_lock_device_for_reset(struct usb_device *udev,
> extern int usb_reset_device(struct usb_device *dev);
> extern void usb_queue_reset_device(struct usb_interface *dev);
>
> +#ifdef CONFIG_ACPI
> +extern int usb_acpi_set_power_state(struct usb_device *hdev, int port,
> + bool enable);
> +extern bool usb_acpi_power_manageable(struct usb_device *hdev, int port);
> +#else
> +static inline int usb_acpi_set_power_state(struct usb_device *hdev, int port,
> + bool enable) { return 0; }
> +static inline bool usb_acpi_power_manageable(struct usb_device *hdev, int port)
> + { return 0; }
is 0 a bool? :)
Please get the types right.
greg k-h
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