Messages in this thread | | | Date | Tue, 10 May 2022 19:52:33 +0300 | From | Vladimir Oltean <> | Subject | Re: [PATCH v2] net: dsa: tag_mtk: add padding for tx packets |
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On Tue, May 10, 2022 at 04:52:16PM +0200, Felix Fietkau wrote: > > On 10.05.22 14:37, Vladimir Oltean wrote: > > On Tue, May 10, 2022 at 11:40:13AM +0200, Felix Fietkau wrote: > > > Padding for transmitted packets needs to account for the special tag. > > > With not enough padding, garbage bytes are inserted by the switch at the > > > end of small packets. > > > > I don't think padding bytes are guaranteed to be zeroes. Aren't they > > discarded? What is the issue? > With the broken padding, ARP requests are silently discarded on the receiver > side in my test. Adding the padding explicitly fixes the issue. > > - Felix
Ok, I'm not going to complain too much about the patch, but I'm still curious where are the so-called "broken" packets discarded. I think the receiving MAC should be passing up to software a buffer without the extra padding beyond the L2 payload length (at least that's the behavior I'm familiar with).
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