On Tue, 2011-10-18 at 11:13 -0700, Stephen Hemminger wrote: > On Tue, 18 Oct 2011 04:43:06 +0100 > Ben Hutchings <b...@decadent.org.uk> wrote: > > > On Mon, 2011-10-17 at 10:40 +0300, Antti Salmela wrote: > > > Package: linux-2.6 > > > Version: 3.0.0-5 > > > Severity: normal > > > > > > > > > sky2 loses packets on 3.0 (-3 and -5) and 3.1-rc7, 2.6.32-38 and > > > setting interface to promiscuous works. > > > > > > [ 60.118244] sky2 0000:02:00.0: eth0: rx error, status 0xb92100 length > > > 185 > > > [ 62.664370] sky2 0000:02:00.0: eth0: rx error, status 0x602100 length > > > 96 > > > [ 63.370051] sky2 0000:02:00.0: eth0: rx error, status 0x422100 length > > > 66 > > > [ 63.714672] sky2 0000:02:00.0: eth0: rx error, status 0x722100 length > > > 114 > > > [ 64.513458] device eth0 entered promiscuous mode > > > > It looks like this is a bug in accounting of VLAN tags, though I don't > > see what difference promiscuous mode should make. > > > > The log messages show that status has the VLAN flag (bit 13) set and the > > length field (bits 16:28) equals the length passed into sky2_receive(), > > but that function expects the length field to be greater by VLAN_HLEN. > > > > This device is: > > > > [...] > > > 02:00.0 Ethernet controller [0200]: Marvell Technology Group Ltd. 88E8053 > > > PCI-E Gigabit Ethernet Controller [11ab:4362] (rev 19) > > > Subsystem: ASUSTeK Computer Inc. Marvell 88E8053 Gigabit Ethernet > > > controller PCIe (Asus) [1043:8142] > > > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > > > Stepping- SERR- FastB2B- DisINTx+ > > > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- > > > <MAbort- >SERR- <PERR- INTx- > > > Latency: 0, Cache Line Size: 16 bytes > > > Interrupt: pin A routed to IRQ 43 > > > Region 0: Memory at cdefc000 (64-bit, non-prefetchable) [size=16K] > > > Region 2: I/O ports at c800 [size=256] > > > Expansion ROM at cdec0000 [disabled] [size=128K] > > > Capabilities: <access denied> > > > Kernel driver in use: sky2 > > [...] > > The accounting is supposed to be: > MAC = total length of packet (including vlan) > DMA = bytes dma'd to buffer (does not include vlan) > Looks like the code is incorrect for the case where hardware > VLAN stripping is disabled.
But if that's true, I'd expect to see these errors in 2.6.32 (where VLAN tag extraction is disabled until a VLAN group is created) and not in 3.0 (where it is enabled by default). Instead it's 3.0 that is broken. I also don't see why changing promiscuous mode would make a difference. > What happens is that status bit > still has the VLAN flag, but DMA engine leaves the VLAN tag > in the DMA buffer so the check fails. > > Proper accounting would involve more state machine mechanics > about whether VLAN tag has already been seen in current receive > status ring. Shouldn't you should restart the relevant queue when changing VLAN tag extraction/insertion? > For now probably best to do something like: > > --- net-next.orig/drivers/net/ethernet/marvell/sky2.c 2011-10-18 > 11:09:04.108683763 -0700 > +++ net-next/drivers/net/ethernet/marvell/sky2.c 2011-10-18 > 11:09:53.661264323 -0700 > @@ -2543,7 +2543,8 @@ static struct sk_buff *sky2_receive(stru > struct sk_buff *skb = NULL; > u16 count = (status & GMR_FS_LEN) >> 16; > > - if (status & GMR_FS_VLAN) > + if ((dev->features & NETIF_F_HW_VLAN_RX) && > + (status & GMR_FS_VLAN)) > count -= VLAN_HLEN; /* Account for vlan tag */ It looks like this is needed to restore the workaround for broken status flags on the FE+. But I doubt it will fix this problem. Ben. > netif_printk(sky2, rx_status, KERN_DEBUG, dev, > > > > > -- Ben Hutchings 73.46% of all statistics are made up.
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