lkml.org 
[lkml]   [2012]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC]Is usb port number fixed?
On Tue, Apr 24, 2012 at 10:14:05AM -0400, Alan Stern wrote:
> In drivers/usb/core/hub.c, look through the hub_events() routine.
> There are several function calls similar to this one:
>
> ret = hub_port_status(hub, i,
> &portstatus, &portchange);
>
> Here i is the port number. This asks the hub to send back status and
> change information for port i. (See also the code for the
> hub_port_status() and get_port_status() routines.)

Thanks, I get it.

On Tue, Apr 24, 2012 at 07:52:44PM +0530, anil wrote:
> The USB specification Table 11-13 describes the hub descriptor in
> detail.
> The following data structure struct usb_hub_descriptor defined in
> "drivers/usb/core/hub.h" of Linux Kernel source contains information
> about the hub descriptor,
>
> struct usb_hub_descriptor {
> _u8 bDescLength;
> _u8 bDescriptorType;
> _u8 bNbrPorts;
> _le16 wHubCharacteristics;
> _u8 bPwrOn2PwrGood;
> _u8 bHubContrCurrent;
> }
>
> The bNbrPorts member contains information on the number of
> downstream-facing ports the hub supports. The structure which i have
> provided is in reference to Linux Kernel Version 2.6 series for Linux
> Kernel Version 3.0+, Please consult an expert.
> Is this information you wanted?
>

Yes, It is want I wanted.But maybe "11.5.3.1 Labeling" show more footprint.

Thanks, all guys.
All you give me a very good explanation about the sentence below:

"High quality support from experts available instantly over the Internet at
no charge has played a major role in stitching together a huge Linux community"

which come from the <<Essential Linux Device Drivers>>.

Cheers.

Udknight


\
 
 \ /
  Last update: 2012-04-24 18:03    [W:0.059 / U:0.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site