Re: HID device communication problem with kernel 2.4
Szilvási Bertalan <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
Hi again, After some serious investigation problem is solved. And the key of the solution is contained by this listgroup.. :-). As it turned out from this mail http://www.mail-archive.com/[email protected]/msg13486.html , duplicate messages are filtered out in kernel 2.4. I do not understand why it works so, and the surrounding kernel code is also strange for me. If I comment out that line, it works fine. Keeping the kernel intact, two queries that provide different answers work also fine, giving opportunity to hack a horrible workaround in the tool. 2.6 kernel code is free from that ominous filtering. Pete, thank you for your reply, and you all take care: Berci -----Original Message----- From: Pete Zaitcev [mailto:[email protected]] Sent: Friday, June 22, 2007 12:24 AM To: Szilvási Bertalan Cc: [email protected]; [email protected] Subject: Re: HID device communication problem with kernel 2.4 On Thu, 21 Jun 2007 22:39:32 +0200, Szilvási Bertalan <[email protected]> wrote: > Communication is done with blocks of 9 values. I send 9 usage_refs to > the device using HIDIOCSUSAGE and HIDIOCSREPORT ioctl calls, and wait > for the reply. Using cat /dev/usb/hiddev0 I can see that answer has > arrived. But only at the first time! After that, no reply arrives, > until I press a button on the device. Then the button pressed data can > be seen, and after that the serial number query works correctly again > for _one_ time, and stops working until the next button event. Setting > LEDs and reading button events work always. It seems that only messages that need reply from the device fail. I see your message, but I don't have an immediate answer. Devices routinely communicate blocks of values. This needs looking into. It may be something as simple as a missing wake_up(), but I don't know. Please let me know if you uncover something new and/or come with a patch. -- Pete ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel