| 1 |
Thank you for all the answers so far:) |
| 2 |
|
| 3 |
Jarry explained the bandwidth a printer consume cannot be too high for |
| 4 |
USB 2.0 slots. This knowledge is very helpful, however at this moment |
| 5 |
the sparc box only have USB 1.x slot, driven by ohci, as I explained. |
| 6 |
|
| 7 |
Richard Fish kindly explained the mechanism behind print processing, a |
| 8 |
printer make take a lot of time to process the data already sent. In my |
| 9 |
case I completely forgot to mension I was using inkjets, the inkjet |
| 10 |
takes rastered image data produced by GutenPrint. Thus I assume most |
| 11 |
image processing is done on the print server, which is usually at 30% |
| 12 |
load when printing, that means it should be able to handle another |
| 13 |
printer. |
| 14 |
|
| 15 |
Richard also suggested upgrading to a network printer, so far it is a |
| 16 |
very good solution too for my case. |
| 17 |
|
| 18 |
I think James provided most helpful information for my case, and thank |
| 19 |
you for so detailed and careful explanation. As he suggested I try to |
| 20 |
look for more hadwar data. It turns that my USB device is not USB 2.0 |
| 21 |
but I also noticed the two USB slots have diferent membase and IRQ. |
| 22 |
|
| 23 |
I wish to compare the sparc station with my desktop. On my x86 desktop |
| 24 |
there are 4 USB slots, dmesg shows that two UHCI device discovered, |
| 25 |
further on each device, a uhub of two slots are discovered. From my |
| 26 |
understanding, the situation of "Sharing bandwidth" James described |
| 27 |
should happen between two USB devices on the one same chip, on one uhub. |
| 28 |
For two devices, they perhaps don't share resource. In my case, my two |
| 29 |
USB 1.0 slots seems to be hot using a uhub, shall the two printer |
| 30 |
compete for resource on this situation too? |
| 31 |
|
| 32 |
Another small question I hope someone with professional knowledge can |
| 33 |
help. I was told ECP/bidirectional printer cable can handle 2Mbps data |
| 34 |
transfer, that seems to be suggesting using parallel cable is as good as |
| 35 |
using USB1 cable (as USB1 is supposed to handle 1.2Mbps ony), or even |
| 36 |
better. Is it true? |
| 37 |
|
| 38 |
Here is my lsusb when I just tried to plug another USB printer and make |
| 39 |
all slots occupied. |
| 40 |
# lsusb |
| 41 |
Bus 002 Device 001: ID 0000:0000 |
| 42 |
Bus 002 Device 002: ID 03f0:1617 Hewlett-Packard |
| 43 |
Bus 001 Device 001: ID 0000:0000 |
| 44 |
Bus 001 Device 002: ID 04b8:0005 Seiko Epson Corp. Stylus Printer |
| 45 |
|
| 46 |
Here is part of my dmesg |
| 47 |
host/usb-ohci.c: USB OHCI at membase 0x1ff00520000, IRQ 10,7d4 |
| 48 |
host/usb-ohci.c: usb-02:02.0, NEC Corporation USB |
| 49 |
usb.c: new USB bus registered, assigned bus number 1 |
| 50 |
hub.c: USB hub found |
| 51 |
hub.c: 3 ports detected |
| 52 |
host/usb-ohci.c: USB OHCI at membase 0x1ff00522000, IRQ 10,7d5 |
| 53 |
host/usb-ohci.c: usb-02:02.1, NEC Corporation USB (#2) |
| 54 |
usb.c: new USB bus registered, assigned bus number 2 |
| 55 |
hub.c: USB hub found |
| 56 |
hub.c: 2 ports detected |
| 57 |
hub.c: new USB device 02:02.0-1, assigned address 2 |
| 58 |
usb.c: USB device 2 (vend/prod 0x4b8/0x5) is not claimed by any active |
| 59 |
driver. |
| 60 |
usb.c: registered new driver hid |
| 61 |
hid-core.c: v1.8.1 Andreas Gal, Vojtech Pavlik <vojtech@××××.cz> |
| 62 |
hid-core.c: USB HID support drivers |
| 63 |
usb.c: registered new driver usblp |
| 64 |
printer.c: usblp0: USB Bidirectional printer dev 2 if 0 alt 0 proto 2 |
| 65 |
vid 0x04B8 pid 0x0005 |
| 66 |
printer.c: v0.13: USB Printer Device Class driver |
| 67 |
|
| 68 |
|
| 69 |
-- |
| 70 |
gentoo-user@g.o mailing list |
Archives