On 2012年06月14日 03:30, Greg KH wrote:
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.
Ok. But in some places, for example
dev_dbg(&hdev->dev, "The power of hub port %d was set to %s\n",
port1, enable ? "enable" : "disable");
try to print two result. ?: is more convenient. If I use "if" statement,
that will be
if (enable)
result = "enable";
else
result = "disable";
dev_dbg(&hdev->dev, "The power of hub port %d was set to %s\n",
port1, result);
This just looks a little complex.
+}
+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?
In my code, usb_acpi_power_manageable() is invoked before
usb_acpi_set_power_state().
Do you mean I should call usb_acpi_power_manageable() in the
usb_acpi_set_power_state()?
+ 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?
Ok.
+
+ 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?
Yeah. Thanks for you suggestion. I will do it.
+ 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.
So careless. Thanks for reminder.
greg k-h
--
Best Regards
Tianyu Lan
linux kernel enabling team
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