On Mon, Feb 19, 2018 at 01:01:07PM +0100, Richard Leitner wrote:
> From: Richard Leitner <richard.leitner@xxxxxxxxxxx>
>
> For some userspace applications information on the number of
> over-current conditions at specific USB hub ports is relevant. Therefore
> introduce a oc_counter in the usb port struct which is exported via
> sysfs.
>
> Signed-off-by: Richard Leitner <richard.leitner@xxxxxxxxxxx>
> ---
> Tested on an i.MX6DL based board.
> ---
> drivers/usb/core/hub.c | 4 +++-
> drivers/usb/core/hub.h | 1 +
> drivers/usb/core/port.c | 10 ++++++++++
> 3 files changed, 14 insertions(+), 1 deletion(-)
When you add/remove/modify a sysfs attribute, you always have to
document in Documentation/ABI/
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index c5c1f6cf3228..448fba1e1827 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -5104,8 +5104,10 @@ static void port_event(struct usb_hub *hub, int port1)
>
> if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
> u16 status = 0, unused;
> + port_dev->oc_count++;
>
> - dev_dbg(&port_dev->dev, "over-current change\n");
> + dev_dbg(&port_dev->dev, "over-current change #%u\n",
> + port_dev->oc_count);
> usb_clear_port_feature(hdev, port1,
> USB_PORT_FEAT_C_OVER_CURRENT);
> msleep(100); /* Cool down */
> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> index 2a700ccc868c..b5cf567bf9e2 100644
> --- a/drivers/usb/core/hub.h
> +++ b/drivers/usb/core/hub.h
> @@ -100,6 +100,7 @@ struct usb_port {
> unsigned int is_superspeed:1;
> unsigned int usb3_lpm_u1_permit:1;
> unsigned int usb3_lpm_u2_permit:1;
> + unsigned int oc_count;
> };
>
> #define to_usb_port(_dev) \
> diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
> index 1a01e9ad3804..0bfe410eb8a7 100644
> --- a/drivers/usb/core/port.c
> +++ b/drivers/usb/core/port.c
> @@ -41,6 +41,15 @@ static ssize_t connect_type_show(struct device *dev,
> }
> static DEVICE_ATTR_RO(connect_type);
>
> +static ssize_t oc_count_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct usb_port *port_dev = to_usb_port(dev);
> +
> + return sprintf(buf, "%u\n", port_dev->oc_count);
> +}
> +static DEVICE_ATTR_RO(oc_count);
I don't see what userspace can do with this number, as there's not much
it can do with it.
thanks,
greg k-h
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