On Mon, 16 Jan 2006, Warren wrote: > Looks better when I re-read it in mono-space - I guess the 100mA MxPwr > entry might have something to do with it. Is there any way I can tell > the USB subsystem to increase that when it sees this device?
No. In fact, the USB subsystem does not _decrease_ the power in the first place. As I've said before, there's no way for the USB subsystem to change the power. The only way that number gets used is that Linux won't configure the device if the max power is too high. (It will still allow you to configure the device by hand if you want to.) But even in an unconfigured state, a USB device is allowed to draw 100 mA. A configured device is allowed to draw up to 500 mA -- but not if its descriptor says that it will only use 100! The fact remains, if the BlackBerry tried to draw 500 mA of current it would succeed, since the available power level can't be reduced. > Warren wrote: > > When I plug it in, dmesg shows: > > usb 3-2: new full speed USB device using address 5 > > > > in /proc/bus/usb/devices it lists as: > > T: Bus=03 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 5 Spd=12 MxCh= 0 > > D: Ver= 1.10 Cls=ff(vend.) Sub=ff Prot=ff MxPS=64 #Cfgs= 1 > > P: Vendor=0fca ProdID=0001 Rev= 1.04 > > S: Manufacturer=Research In Motion > > S: Product=Terminal mobile RIM > > C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA > > I: If#= 0 Alt= 0 #EPs= 4 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none) > > E: Ad=81(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms > > E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms > > E: Ad=83(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms > > E: Ad=04(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms > > > > The BB is the only USB device I have plugged in to the machine. Okay, so clearly Linux knows the device is plugged in and the USB controller is not in power-saving mode. There is one possible explanation. It could be that the BlackBerry has to be told before it will recharge at the faster rate. In Windows there may be a driver that handles this. On your Linux system there is no driver for the BlackBerry, as can be seen above. Here's a simple test, if you're curious. In your computer's BIOS setup, turn on USB legacy support. Then when you start up, just sit at the multi-boot prompt. Don't load any operating system. That way there's no question about drivers or anything else confusing the issue. See how long it takes to recharge the iPod/BlackBerry; if it takes a long time then you'll know that Linux hasn't done anything special to reduce the power levels. Alan Stern ------------------------------------------------------- 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
