I was pretty skeptical when I looked at the patch because my drivers that talk directly to the usb-core use bulk writes if the kernel version is 2.4.21 or 22 (because ints were broken in those versions). But, after applying the patch to usb-core the system works as expected and I can both read and write to the hiddev.
Now it is time for me to overcome the "hid-core.c: output queue full" issue. Progress is great! John, thanks for the pointer and help!!! Scott > -----Original Message----- > From: John Cheevers [mailto:[EMAIL PROTECTED] > Sent: Tuesday, February 17, 2004 9:49 PM > To: [EMAIL PROTECTED] > Subject: Re: [linux-usb-devel] How do I write 8 bytes to a > HIDDEV device? > > > > Scott Hiles wrote: > > > I have a device (PowerLinc USB) that sends and receives 8 > bytes of data. > For reading, upon receiving an event I read > the report, then the > field, and > > then read the usage 8 times with the usage_index > incremented for each > read. > > It works perfectly. > > > Now, when I try to reverse that process with the following > code, the > system > > gives an error "usb_submit_urb(out)" and the HID system > stops responding. > This is all under kernel 2.6.0 and 2.6.1. > > Keep going... you need 2.6.1-rc1. > > The hid-core.c patch described here > > http://marc.theaimsgroup.com/?l=linux-usb-> devel&m=107357664829164&w=2 > is necessary. > > The reason the bug causes the HID system to stop responding > is described > here: > > http://marc.theaimsgroup.com/?l=linux-usb-> devel&m=107388393607401&w=2 > That bug is still there, for the moment, but no longer gets exercised. > > > Have I oversimplified my assumption that writing is the reverse of > reading > > using the usage calls? > > The code you included is the correct way to do it. I have > the same PowerLinc device working with identical code. > (Except check your ioctl return values for EBUSY) > > Later, > Charles Lepple wrote: > > > Given the large installed user base with the (somewhat > broken) hiddev > kernel driver, I can see the appeal [to > using hiddev], but you may want > to consider the > libhid/libusb approach. > > Hiddev works for me. Can you elaborate on what else might be > broken and should be looked at? > > John Cheevers > > > > > > > ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id56&alloc_id438&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
