Re: Sierra Wireless (MC8780) HSDPA speed issue

From: Ralf Nyren
Date: Sat Mar 14 2009 - 15:34:56 EST


Hi,

I choose to only test download speeds for now but upload will also be of
interest later on.

I had actually tried to change the N_IN_URB/N_OUT_URB before sending of the
report but now I've been testing with both 8 and 128 but the speed remains the
same. Download speed max 1.0Mbit/s in Linux while the Windows driver could get
an average of 2.5Mbit/s at my current location (different location than during
the last test).

I have also tried the new 1.6.0 driver as kindly supplied by Sierra but the
speed remained the same 1.0Mbit/s with the new driver as well...

Anything else you think I could try?

Best regards, Ralf


On Fri, 13 Mar 2009, Greg KH wrote:


Are you testing up or down speeds?

If you want to, and you think the driver is the problem, try changing
the values in drivers/usb/serial/sierra.c:
/* per port private data */
#define N_IN_URB 4
#define N_OUT_URB 4
#define IN_BUFLEN 4096

Try bumping up the N_IN_URB and N_OUT_URB values a bunch and let me know
if things go faster now.

thanks,

greg k-h

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