Hi BR,
> Dear Amitkumar Karwar,
>
> some additional info.
>
> On Thu, Sep 11, 2014 at 5:09 PM, Amitkumar Karwar <akarwar@xxxxxxxxxxx>
> wrote:
> > Hi BR,
> >
> >>
> >> I'm using 3.9 mainline mwifiex driver for wireless usb card. Doing
> >> some throughput testing (with iperf) in 5GHz I got following
> failures:
> >> [ 221.521799] usb 1-1: mwifiex_usb_submit_rx_urb: dev_alloc_skb
> >> failed
> >
> > This is skb allocation failure returned by kernel. 4k buffer is
> always allocated for Rx packets. This issue doesn't seem to be specific
> to 5Ghz.
> Yes you're right. I can reproduce issue also with 2.4GHz (doing iperf
> testing as mentioned in other email) by pinging device with card.
> >
> >>
> >> I checked which which size fails to allocate and it's 4096 bytes. I
> >> was looking to changes in never kernel releases but I cannot find
> >> anything obvious. When connected to 2.4GHz I cannot reproduce issue
> >> though. I'm using FW version mwifiex 1.0 (14.68.29.p26).
> >>
> >
> > Could you please provide the platform details?
> > How often the problem occurs during throughput testing? Are there any
> specific steps?
> One more observation is that when problem occurred complete system is
> unresponsive (console is almost completely dead).
Thanks for the more information.
Skb alloc failure should be gracefully handled. We will look into this issue.
> I can workaround issue by decreasing iperf bandwidth to ~40m. I think
> in this situation we're running out of memory by exhaustive skb
> allocations.
Actually 6 4K size buffers are being allocated for Rx and Tx data during traffic.
Probably your platform runs out of memory after these allocations.
Could you please try changing this number(MWIFIEX_TX_DATA_URB/MWIFIEX_RX_DATA_URB macros) to 3?
Regards,
Amitkumar Karwar
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