On Mon, Feb 19, 2018 at 05:05:34PM +0100, Richard Leitner wrote:
>
> On 02/19/2018 04:59 PM, Greg KH wrote:
> > 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/
>
> Ok. Thank you. Seems I missed that, Sorry!
>
> >>
> >> 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.
>
> I've answered this question to Felipe already:
<snip>
It's not described in the patch changelog, which is where it is required
:)
thanks,
greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
