Messages in this thread | | | Date | Mon, 19 Sep 2022 20:31:23 -0400 | Subject | Re: [PATCH] net: sunhme: Fix packet reception for len < RX_COPY_THRESHOLD | From | Sean Anderson <> |
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On 9/19/22 16:39, Andrew Lunn wrote: > On Sun, Sep 18, 2022 at 05:55:34PM -0400, Sean Anderson wrote: >> There is a separate receive path for small packets (under 256 bytes). >> Instead of allocating a new dma-capable skb to be used for the next packet, >> this path allocates a skb and copies the data into it (reusing the existing >> sbk for the next packet). There are two bytes of junk data at the beginning >> of every packet. I believe these are inserted in order to allow aligned >> DMA and IP headers. We skip over them using skb_reserve. Before copying >> over the data, we must use a barrier to ensure we see the whole packet. The >> current code only synchronizes len bytes, starting from the beginning of >> the packet, including the junk bytes. However, this leaves off the final >> two bytes in the packet. Synchronize the whole packet. >> >> To reproduce this problem, ping a HME with a payload size between 17 and 214 >> >> $ ping -s 17 <hme_address> >> >> which will complain rather loudly about the data mismatch. Small packets >> (below 60 bytes on the wire) do not have this issue. I suspect this is >> related to the padding added to increase the minimum packet size. >> >> Signed-off-by: Sean Anderson <seanga2@gmail.com> > > Hi Sean > >> Patch-prefix: net > > This should be in the Subject of the email. Various tools look for the > netdev tree there. Please try to remember that for future patches.
Sorry, it should have been "Series-postfix".
> Please could you add a Fixes: tag indicating when the problem was > introduced. Its O.K. if that was when the driver was added. It just > helps getting the patch back ported to older stable kernels.
Well, the driver was added before git was started...
I suppose I could blame 1da177e4c3f4 ("Linux-2.6.12-rc2"), but maybe I should just CC the stable list?
> I think patchwork allows you to just reply to your post, and it will > automagically append the Fixes: tag when the Maintainer actually > applies the patch. > > Reviewed-by: Andrew Lunn <andrew@lunn.ch> > > Andrew
--Sean
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