On Fri, Dec 11, 2020 at 04:29:14PM +0000, Daniel Thompson wrote: > On Fri, Dec 11, 2020 at 02:01:28PM +0000, Ioana Ciornei wrote: > > On Thu, Dec 10, 2020 at 08:06:36PM +0200, Ioana Ciornei wrote: > > > [Added also the netdev mailing list, I haven't heard of linux-netdev > > > before but kept it] > > > > > > On Thu, Dec 10, 2020 at 05:31:56PM +0000, Daniel Thompson wrote: > > > > Hi Ioana > > > > > > Hi Daniel, > > > > > > > > > > > On Mon, Jun 29, 2020 at 06:47:11PM +0000, Ioana Ciornei wrote: > > > > > Instead of realloc-ing the skb on the Tx path when the provided > > > > > headroom > > > > > is smaller than the HW requirements, create a Scatter/Gather frame > > > > > descriptor with only one entry. > > > > > > > > > > Remove the '[drv] tx realloc frames' counter exposed previously > > > > > through > > > > > ethtool since it is no longer used. > > > > > > > > > > Signed-off-by: Ioana Ciornei <ioana.cior...@nxp.com> > > > > > --- > > > > > > > > I've been chasing down a networking regression on my LX2160A board > > > > (Honeycomb LX2K based on CEx7 LX2160A COM) that first appeared in v5.9. > > > > > > > > It makes the board unreliable opening outbound connections meaning > > > > things like `apt update` or `git fetch` often can't open the connection. > > > > It does not happen all the time but is sufficient to make the boards > > > > built-in networking useless for workstation use. > > > > > > > > The problem is strongly linked to warnings in the logs so I used the > > > > warnings to bisect down to locate the cause of the regression and it > > > > pinpointed this patch. I have confirmed that in both v5.9 and v5.10-rc7 > > > > that reverting this patch (and fixing up the merge issues) fixes the > > > > regression and the warnings stop appearing. > > > > > > > > A typical example of the warning is below (io-pgtable-arm.c:281 is an > > > > error path that I guess would cause dma_map_page_attrs() to return > > > > an error): > > > > > > > > [ 714.464927] WARNING: CPU: 13 PID: 0 at > > > > drivers/iommu/io-pgtable-arm.c:281 __arm_lpae_map+0x2d4/0x30c > > > > [ 714.464930] Modules linked in: snd_seq_dummy(E) snd_hrtimer(E) > > > > snd_seq(E) snd_seq_device(E) snd_timer(E) snd(E) soundcore(E) bridge(E) > > > > stp(E) llc(E) rfkill(E) caam_jr(E) crypto_engine(E) rng_core(E) > > > > joydev(E) evdev(E) dpaa2_caam(E) caamhash_desc(E) caamalg_desc(E) > > > > authenc(E) libdes(E) dpaa2_console(E) ofpart(E) caam(E) sg(E) error(E) > > > > lm90(E) at24(E) spi_nor(E) mtd(E) sbsa_gwdt(E) qoriq_thermal(E) > > > > layerscape_edac_mod(E) qoriq_cpufreq(E) drm(E) fuse(E) configfs(E) > > > > ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc32c_generic(E) crc16(E) > > > > mbcache(E) jbd2(E) hid_generic(E) usbhid(E) hid(E) dm_crypt(E) dm_mod(E) > > > > sd_mod(E) fsl_dpaa2_ptp(E) ptp_qoriq(E) fsl_dpaa2_eth(E) > > > > xhci_plat_hcd(E) xhci_hcd(E) usbcore(E) aes_ce_blk(E) crypto_simd(E) > > > > cryptd(E) aes_ce_cipher(E) ghash_ce(E) gf128mul(E) at803x(E) libaes(E) > > > > fsl_mc_dpio(E) pcs_lynx(E) rtc_pcf2127(E) sha2_ce(E) phylink(E) > > > > xgmac_mdio(E) regmap_spi(E) of_mdio(E) sha256_arm64(E) > > > > i2c_mux_pca954x(E) fixed_phy(E) i2c_mux(E) sha1_ce(E) ptp(E) libphy(E) > > > > [ 714.465131] pps_core(E) ahci_qoriq(E) libahci_platform(E) nvme(E) > > > > libahci(E) nvme_core(E) t10_pi(E) libata(E) crc_t10dif(E) > > > > crct10dif_generic(E) crct10dif_common(E) dwc3(E) scsi_mod(E) udc_core(E) > > > > roles(E) ulpi(E) sdhci_of_esdhc(E) sdhci_pltfm(E) sdhci(E) > > > > spi_nxp_fspi(E) i2c_imx(E) fixed(E) > > > > [ 714.465192] CPU: 13 PID: 0 Comm: swapper/13 Tainted: G W E > > > > 5.10.0-rc7-00001-gba98d13279ca #52 > > > > [ 714.465196] Hardware name: SolidRun LX2160A Honeycomb (DT) > > > > [ 714.465202] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) > > > > [ 714.465207] pc : __arm_lpae_map+0x2d4/0x30c > > > > [ 714.465211] lr : __arm_lpae_map+0x114/0x30c > > > > [ 714.465215] sp : ffff80001006b340 > > > > [ 714.465219] x29: ffff80001006b340 x28: 0000002086538003 > > > > [ 714.465227] x27: 0000000000000a20 x26: 0000000000001000 > > > > [ 714.465236] x25: 0000000000000f44 x24: 00000020adf8d000 > > > > [ 714.465245] x23: 0000000000000001 x22: 0000fffffaeca000 > > > > [ 714.465253] x21: 0000000000000003 x20: ffff19b60d64d200 > > > > [ 714.465261] x19: 00000000000000ca x18: 0000000000000000 > > > > [ 714.465270] x17: 0000000000000000 x16: ffffcccb7cf3ca20 > > > > [ 714.465278] x15: 0000000000000000 x14: 0000000000000000 > > > > [ 714.465286] x13: 0000000000000003 x12: 0000000000000010 > > > > [ 714.465294] x11: 0000000000000000 x10: 0000000000000002 > > > > [ 714.465302] x9 : ffffcccb7d5b6e78 x8 : 00000000000001ff > > > > [ 714.465311] x7 : ffff19b606538650 x6 : ffff19b606538000 > > > > [ 714.465319] x5 : 0000000000000009 x4 : 0000000000000f44 > > > > [ 714.465327] x3 : 0000000000001000 x2 : 00000020adf8d000 > > > > [ 714.465335] x1 : 0000000000000002 x0 : 0000000000000003 > > > > [ 714.465343] Call trace: > > > > [ 714.465348] __arm_lpae_map+0x2d4/0x30c > > > > [ 714.465353] __arm_lpae_map+0x114/0x30c > > > > [ 714.465357] __arm_lpae_map+0x114/0x30c > > > > [ 714.465362] __arm_lpae_map+0x114/0x30c > > > > [ 714.465366] arm_lpae_map+0xf4/0x180 > > > > [ 714.465373] arm_smmu_map+0x4c/0xc0 > > > > [ 714.465379] __iommu_map+0x100/0x2bc > > > > [ 714.465385] iommu_map_atomic+0x20/0x30 > > > > [ 714.465391] __iommu_dma_map+0xb0/0x110 > > > > [ 714.465397] iommu_dma_map_page+0xb8/0x120 > > > > [ 714.465404] dma_map_page_attrs+0x1a8/0x210 > > > > [ 714.465413] __dpaa2_eth_tx+0x384/0xbd0 [fsl_dpaa2_eth] > > > > [ 714.465421] dpaa2_eth_tx+0x84/0x134 [fsl_dpaa2_eth] > > > > [ 714.465427] dev_hard_start_xmit+0x10c/0x2b0 > > > > [ 714.465433] sch_direct_xmit+0x1a0/0x550 > > > > [ 714.465438] __qdisc_run+0x140/0x670 > > > > [ 714.465443] __dev_queue_xmit+0x6c4/0xa74 > > > > [ 714.465449] dev_queue_xmit+0x20/0x2c > > > > [ 714.465463] br_dev_queue_push_xmit+0xc4/0x1a0 [bridge] > > > > [ 714.465476] br_forward_finish+0xdc/0xf0 [bridge] > > > > [ 714.465489] __br_forward+0x160/0x1c0 [bridge] > > > > [ 714.465502] br_forward+0x13c/0x160 [bridge] > > > > [ 714.465514] br_dev_xmit+0x228/0x3b0 [bridge] > > > > [ 714.465520] dev_hard_start_xmit+0x10c/0x2b0 > > > > [ 714.465526] __dev_queue_xmit+0x8f0/0xa74 > > > > [ 714.465531] dev_queue_xmit+0x20/0x2c > > > > [ 714.465538] arp_xmit+0xc0/0xd0 > > > > [ 714.465544] arp_send_dst+0x78/0xa0 > > > > [ 714.465550] arp_solicit+0xf4/0x260 > > > > [ 714.465554] neigh_probe+0x64/0xb0 > > > > [ 714.465560] neigh_timer_handler+0x2f4/0x400 > > > > [ 714.465566] call_timer_fn+0x3c/0x184 > > > > [ 714.465572] __run_timers.part.0+0x2bc/0x370 > > > > [ 714.465578] run_timer_softirq+0x48/0x80 > > > > [ 714.465583] __do_softirq+0x120/0x36c > > > > [ 714.465589] irq_exit+0xac/0x100 > > > > [ 714.465596] __handle_domain_irq+0x8c/0xf0 > > > > [ 714.465600] gic_handle_irq+0xcc/0x14c > > > > [ 714.465605] el1_irq+0xc4/0x180 > > > > [ 714.465610] arch_cpu_idle+0x18/0x30 > > > > [ 714.465617] default_idle_call+0x4c/0x180 > > > > [ 714.465623] do_idle+0x238/0x2b0 > > > > [ 714.465629] cpu_startup_entry+0x30/0xa0 > > > > [ 714.465636] secondary_start_kernel+0x134/0x180 > > > > [ 714.465640] ---[ end trace a84a7f61b559005f ]--- > > > > > > > > > > > > Given it is the iommu code that is provoking the warning I should > > > > probably mention that the board I have requires > > > > arm-smmu.disable_bypass=0 on the kernel command line in order to boot. > > > > Also if it matters I am running the latest firmware from Solidrun > > > > which is based on LSDK-20.04. > > > > > > > > > > Hmmm, from what I remember I think I tested this with the smmu bypassed > > > so that is why I didn't catch it. > > > > > > > Is there any reason for this code not to be working for LX2160A? > > > > > > I wouldn't expect this to be LX2160A specific but rather a bug in the > > > implementation.. sorry. > > > > > > Let me reproduce it and see if I can get to the bottom of it and I will > > > get back with some more info. > > > > > > > Hi Daniel, > > > > It seems that the dma-unmapping on the SGT buffer was incorrectly done > > with a zero size since on the Tx path I initialized the improper field. > > > > Could you test the following diff and let me know if you can generate > > the WARNINGs anymore? > > I fired this up and, with your change, I've not been able to trigger > the warning with the tests that I used the drive my bisect. >
Great, thanks for testing this. I will take care of sending the fix to -net. Ioana > Thanks for the quick response. > > > Daniel. > > > > > > --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c > > +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c > > @@ -878,7 +878,7 @@ static int dpaa2_eth_build_sg_fd_single_buf(struct > > dpaa2_eth_priv *priv, > > swa = (struct dpaa2_eth_swa *)sgt_buf; > > swa->type = DPAA2_ETH_SWA_SINGLE; > > swa->single.skb = skb; > > - swa->sg.sgt_size = sgt_buf_size; > > + swa->single.sgt_size = sgt_buf_size; > > > > /* Separately map the SGT buffer */ > > sgt_addr = dma_map_single(dev, sgt_buf, sgt_buf_size, > > DMA_BIDIRECTIONAL); > > > > > > Ioana
