Dear Alan, I would like to apologize if I insulted you or anybody by saing "Linux has a problem". I only meant to say that something strange is happening. I do not consider myself an expert on USB, I just have general knowledge of electronics and logic.
I also said that it _appears_ to be a power problem. Why did I come to this conclusion. I have a PCI USB 2.0 card which has a power connector. I did not connect the power cable to it and some of USB devices worked OK, but my external drive did not. It would crash on copies of large files. Forcing it to USB1.1 mode did not help. I noticed that when the power of the drive is off, its light is still on, indicating connection to the USB bus. This is how I concluded that the USB-IDE controller gets its power from the USB host. (I could have opened the enclose to see this too). After that, and searching on the web, I saw reports that connecting a drive via powered USB hub helps. What it told me is that powered hub supplies more power than the host controller. Since I do not have a hub, but the PCI card had this power connector, I finally connected the power to it. Interestingly enough, the drive started to work perfectly in USB1.1 mode. In USB 2.0 mode, it still crashes on large copies, but now I can copy about 1G file (compared to 100M before). From windows, on the same system, the drive works. This exact same drive works perfectly on another Linux system (which has different hardware). Putting this all together, I have concluded that :"It _appears_ to me, there are problems with the power" Your explanation about the power features of USB system makes perfect sence to me and I do not see how windows can do anything different (better) from Linux. Maybe, and this is possible, Windows can reconfigure the device to draw different amounts of power depending on something? This is the only way it could happen. In the case of iPod and the such, I can see why the device might not be charging if it is not told to charge by appropriate driver. But I do not see how IDE-USB can draw more or less power depending on what??... By the way, the drive has Genesys logic IDE-USB controller, and as I said works fine on my other Linux system (laptop) and does not work in USB2 mode on my Linux desktop. With best wishes, Lazar > For the disk drive these questions don't arise -- obviously the unit > lets > Linux know when it is plugged in. And maybe it does have problems... > but > how can you be sure those problems are at all related to the power > supply? > > Alan Stern > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------------------------------- 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-users
