ubsa speed limit

[Adam McDougall]

Dominic Fandrey wrote:
> When I download a single file it seems that the download speed is 
> limited to 32k (raw data as shown by netstat). Under Windows I can 
> reach values around 60k. I can achieve more throughput (though not as 
> much as under Windows), when downloading several files at once.
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Try this hack, its using concepts I gathered from people patching the 
Linux driver, basically increasing the block size of transfers.

Edit ubsa.c and recompile/reload the ubsa driver.  Its located around 
line 362.  Basically replace UGETW(ed->wMaxPacketSize); or 
UGETW(ed->wMaxPacketSize); with 2048.  I think the default is 512 and 
you can play with different values to evaluate its effect on speed.  I 
realized a large performance boost from 2048, I think at least 80k/sec 
transfer rate.

                } else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
                    UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK) {
                        ucom->sc_bulkin_no = ed->bEndpointAddress;
-                       ucom->sc_ibufsize = UGETW(ed->wMaxPacketSize);
+                       ucom->sc_ibufsize = 2048;
+                       // ucom->sc_ibufsize = UGETW(ed->wMaxPacketSize);
                } else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT &&
                    UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK) {
                        ucom->sc_bulkout_no = ed->bEndpointAddress;
-                       ucom->sc_obufsize = UGETW(ed->wMaxPacketSize);
+                       ucom->sc_obufsize = 2048;
+                       // ucom->sc_obufsize = UGETW(ed->wMaxPacketSize);
                }
        }