Thanks for your time.
Alan Stern wrote:
> You must not have sent a Set-Port-Feature request. This warning gets
> invoked only when the recipient part of bRequestType is ENDPOINT or
> INTERFACE, and for Set-Port-Feature the recipient is OTHER.
[...]
> You are allowed to send control messages whose recipient is anything other
> than ENDPOINT or INTERFACE, and you are allowed to send those as well if
> the type is VENDOR.
Could you please take a deep breath, Alan? I think that I am not your
enemy, never. It would be good if we share the problem and cooperate
together.
Your explanation (what I quoted here) is correct. But the my
requirement is not only for Set-Port-Feature, but also for
Clear-Port-Feature.
Here is some more explanation to the people who have interest on this
topic.
We need to send a Clear-Port-Feature to turn off the port power, and a
Set-Port-Feature to turn on the port power. That's my understanding.
(When I connect my hub, the port power is on.)
The answer of the quiz is that when I didn't success with libusb
library, my invocation was with USB_REQ_CLEAR_FEATURE.
Right, in drivers/usb/core/devio.c, there is a function
check_ctrlrecip, and only when requesttype is ENDPOINT or INTERFACE,
it is checked. Here is a quote of a part of check_ctrlrecip:
switch (requesttype & USB_RECIP_MASK) {
case USB_RECIP_ENDPOINT:
if ((ret = findintfep(ps->dev, index)) >= 0)
ret = checkintf(ps, ret);
break;
case USB_RECIP_INTERFACE:
ret = checkintf(ps, index);
break;
}
What's USB_RECIP_MASK? It is defined in include/linux/usb_ch9.h:
#define USB_RECIP_MASK 0x1f
#define USB_RECIP_DEVICE 0x00
#define USB_RECIP_INTERFACE 0x01
#define USB_RECIP_ENDPOINT 0x02
#define USB_RECIP_OTHER 0x03
And the values of Clear-Port-Feature and Set-Port-Feature are:
#define USB_REQ_CLEAR_FEATURE 0x01
#define USB_REQ_SET_FEATURE 0x03
Yes, it is OTHER for Set-Port-Feature. It is INTERFACE for
Clear-Port-Feature.
--
-------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc. Do you grep through log files
for problems? Stop! Download the new AJAX search engine that makes
searching your log files as easy as surfing the web. DOWNLOAD SPLUNK!
http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
