Re: USB 2.0 Mass storage device

From: Jason Munro
Date: Thu Feb 24 2005 - 16:52:02 EST


On 3:38:53 pm 02/24/05 Lukas Hejtmanek <xhejtman@xxxxxxxxxxxx> wrote:
> This is another device (Card reader) supporting USB 2.0.
>
> In this case I used only uhci_hcd driver and it reports speed 12.
>
> T: Bus=04 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 3 Spd=12 MxCh= 0
> D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
> P: Vendor=05dc ProdID=b018 Rev= 1.28
> S: Manufacturer=Lexar Media
> S: Product=Multi-Card Reader
> S: SerialNumber=0000246504
> C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=500mA
> I: If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50
> Driver=usb-storage E: Ad=81(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
> E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
>
> In this case I used both ehci_hcd and uhci_hcd drivers (ehci detected
> device) and it reports speed 480.
>
> T: Bus=01 Lev=01 Prnt=01 Port=04 Cnt=01 Dev#= 2 Spd=480 MxCh= 0
> D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
> P: Vendor=05dc ProdID=b018 Rev= 1.28
> S: Manufacturer=Lexar Media
> S: Product=Multi-Card Reader
> S: SerialNumber=0000246504
> C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=500mA
> I: If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50
> Driver=usb-storage E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
> E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
>
> So for me it looks like it reports speed according to USB driver or
> negotiated speed.

Same here with a new Seagate external USB 2.0 drive. If plugged into my
laptop which does not have USB 2.0 it shows 12 in /dev/bus/usb/devices,
however on a machine with USB 2.0 support it changes to 480.

\__ Jason Munro
\__ jason@xxxxxxxxxx
\__ http://hastymail.sourceforge.net/

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