2009-06-23 13:35:57

by Prabhu Chawandi

Subject: Not able to read USB speed and descriptor

Hi all,

I ma not able to read the USB descriptor and speeed, while I can
read and write into the storage device..

What might be the reason for that ?

regards,
Prabhu

2009-06-23 14:20:03

by Rajaram R

Subject: Re: Not able to read USB speed and descriptor

On Tue, Jun 23, 2009 at 9:27 PM, Prabhu
Chawandi<[email protected]> wrote:
> Hi all,
>
> ? I ma not able to read the USB descriptor and speeed, while I can
> read and write into the storage device..
>
> What might be the reason for that ?

Where is the code ?

>
> regards,
> Prabhu
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2009-06-24 07:21:56

by Prabhu Chawandi

Subject: Re: Not able to read USB speed and descriptor

In the devio.c,

I have added a case to return the speed and other descriptors,

call :
ret = usb_control_msg(pRootHub, usb_sndctrlpipe(pRootHub, 0),
USB_REQ_CLEAR_FEATURE, USB_RT_PORT, USB_PORT_FEAT_POWER,
port_num + 1, NULL, 0, HZ);

The above call is returning err : -32 EPIPE.

The above call is working file for the rear port while the same is not
working for the fromt port.


Anythig am I missing ? I am testing it for mass stoage device...


Any inputs ? ,,,,,

On Tue, Jun 23, 2009 at 6:57 PM, Prabhu
Chawandi<[email protected]> wrote:
> Hi all,
>
> ? I ma not able to read the USB descriptor and speeed, while I can
> read and write into the storage device..
>
> What might be the reason for that ?
>
> regards,
> Prabhu
>

2009-06-24 15:01:34

by Alan Stern

Subject: Re: Not able to read USB speed and descriptor

On Wed, 24 Jun 2009, Prabhu Chawandi wrote:

> In the devio.c,
>
> I have added a case to return the speed and other descriptors,
>
> call :
> ret = usb_control_msg(pRootHub, usb_sndctrlpipe(pRootHub, 0),
> USB_REQ_CLEAR_FEATURE, USB_RT_PORT, USB_PORT_FEAT_POWER,
> port_num + 1, NULL, 0, HZ);
>
> The above call is returning err : -32 EPIPE.
>
> The above call is working file for the rear port while the same is not
> working for the fromt port.

Is this question related to $SUBJECT? I don't see any connection...

> Anythig am I missing ? I am testing it for mass stoage device...

In most host controllers for personal computers, the hardware does not
support turning off port power.

Alan Stern