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| author | Richard Leitner <richard.leitner@skidata.com> | 2018-03-20 11:17:13 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-22 13:07:05 +0100 |
| commit | 1cbd53c8cd85a63383a075347abee8f6e3f14fbe (patch) | |
| tree | f80b57ca914df69f6d4cfecb0515bfbb5a40c5e3 /drivers/usb/core/hub.c | |
| parent | e3cb7bde9a6a8bfdee5917facf00afb98fee1821 (diff) | |
| download | linux-stable-1cbd53c8cd85a63383a075347abee8f6e3f14fbe.tar.gz linux-stable-1cbd53c8cd85a63383a075347abee8f6e3f14fbe.tar.bz2 linux-stable-1cbd53c8cd85a63383a075347abee8f6e3f14fbe.zip | |
usb: core: introduce per-port over-current counters
For some userspace applications information on the number of
over-current conditions at specific USB hub ports is relevant.
In our case we have a series of USB hardware (using the cp210x driver)
which communicates using a proprietary protocol. These devices sometimes
trigger an over-current situation on some hubs. In case of such an
over-current situation the USB devices offer an interface for reducing
the max used power. As these conditions are quite rare and imply
performance reductions of the device we don't want to reduce the max
power always.
Therefore give user-space applications the possibility to react
adequately by introducing an over_current_counter in the usb port struct
which is exported via sysfs.
Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core/hub.c')
| -rw-r--r-- | drivers/usb/core/hub.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index ac7bab772a3a..aaeef03c0d83 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->over_current_count++; - dev_dbg(&port_dev->dev, "over-current change\n"); + dev_dbg(&port_dev->dev, "over-current change #%u\n", + port_dev->over_current_count); usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_OVER_CURRENT); msleep(100); /* Cool down */ |