Hello. I've made test with Win2000 driver and succeded to pakc two transactions inside frame. I made posted OUT,OUT,IN,IN requests and after it polling for completions. So seams async URB transactions can do the same in linux. The question is if there is any reference or experiance of doing it from user space. I do not quite understand how to get completion. Will it be sent to my process as signal? Any reference code will be appreciated.
Thank you. -----Original Message----- From: "XOL" <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Date: Thu, 13 Nov 2003 15:34:36 +0300 Subject: [linux-usb-devel] Using asynchronous transactions from user space > > Hello. > I have a USB to I2C adapter. > For a while I was using user space library to access my device. > This library is based on linux usbdevfs driver. I use bulk > transactions. > While the bandwidth of i2c transactions was not important all was fine. Now we need > the device to work faster and I found that the increasing my I2C bus speed do not > actually increase overall performance. The problem is frame granularity. I can make > only one bulk transaction in one frame. This I can see from analyzer. > One I2C read transaction (for example) via my device requires > BULK_OUT - 1ms > BULK_IN - 1ms > ... > And I can't force the system make a number of BULK transactions in > one frame. The windows implementation of driver for my device > has asynchronous request ( from user level ) and this let me > make BULK_IN,BULK_OUT requests posted. This cause the host controller > pack the request in one frame. > In Linux I'm going to use URB post ioctl's provided by usbdevfs driver. > Do you think this will help me? > Should I do something else to fix the problem? > Are there any reference user space code? > The device is based on AnchorChip AN2131 IC. > Thank you. Xol. > > > I'm Macrovision FREE. Copy DVD-VHS,DVD-DVD,VHS-DVD > --== DVD Red PRO ==-- > http://www.dimax.com.ua > http://www.dimax.com.ua/English/dvd_recorder.htm > > > ------------------------------------------------------- > This SF.Net email sponsored by: ApacheCon 2003, > 16-19 November in Las Vegas. Learn firsthand the latest > developments in Apache, PHP, Perl, XML, Java, MySQL, > WebDAV, and more! http://www.apachecon.com/ > _______________________________________________ > [EMAIL PROTECTED] > To unsubscribe, use the last form field at: > https://lists.sourceforge.net/lists/listinfo/linux-usb-devel > I'm Macrovision FREE. Copy DVD-VHS,DVD-DVD,VHS-DVD --== DVD Red PRO ==-- http://www.dimax.com.ua http://www.dimax.com.ua/English/dvd_recorder.htm ------------------------------------------------------- This SF. Net email is sponsored by: GoToMyPC GoToMyPC is the fast, easy and secure way to access your computer from any Web browser or wireless device. Click here to Try it Free! https://www.gotomypc.com/tr/OSDN/AW/Q4_2003/t/g22lp?Target=mm/g22lp.tmpl _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
