lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <1jfshftliz.fsf@starbuckisacylon.baylibre.com> Date: Mon, 29 Aug 2022 12:01:25 +0200 From: Jerome Brunet <jbrunet@...libre.com> To: Heiner Kallweit <hkallweit1@...il.com>, Da Xue <da@...sconfused.com> Cc: Giuseppe Cavallaro <peppe.cavallaro@...com>, Alexandre Torgue <alexandre.torgue@...s.st.com>, Jose Abreu <joabreu@...opsys.com>, Erico Nunes <nunes.erico@...il.com>, netdev@...r.kernel.org, linux-amlogic@...ts.infradead.org, Kevin Hilman <khilman@...libre.com>, Neil Armstrong <narmstrong@...libre.com>, Vyacheslav <adeep@...ina.in>, Qi Duan <qi.duan@...ogic.com> Subject: Re: [RFC/RFT PATCH] net: stmmac: do not poke MAC_CTRL_REG twice on link up On Fri 26 Aug 2022 at 22:36, Heiner Kallweit <hkallweit1@...il.com> wrote: > On 26.08.2022 17:45, Da Xue wrote: >> Hi Heiner, >> >> I have been running with the patch reverted for about two weeks now >> without issue but I have a modified u-boot with ethernet bringup >> disabled. >> >> If u-boot brings up ethernet, all of the GXL boards with more than 1GB >> memory experience various bugs. I had to bring the PHY initialization >> patch into Linux proper: >> https://github.com/libre-computer-project/libretech-linux/commit/1a4004c11877d4239b57b182da1ce69a81c0150c >> > Thanks for the follow-up. To be acceptable upstream I'm pretty sure that > the maintainer is going to request replacing magic number 0x10110181 > with or'ing proper constants for the respective bits and fields. > >> Hope this helps someone. >> >> Best, >> >> Da >> >> On Fri, Aug 26, 2022 at 5:51 AM Heiner Kallweit <hkallweit1@...il.com> wrote: >>> >>> On 07.07.2022 12:14, Jerome Brunet wrote: >>>> For some reason, poking MAC_CTRL_REG a second time, even with the same >>>> value, causes problem on a dwmac 3.70a. >>>> >>>> This problem happens on all the Amlogic SoCs, on link up, when the RMII >>>> 10/100 internal interface is used. The problem does not happen on boards >>>> using the external RGMII 10/100/1000 interface. Initially we suspected the >>>> PHY to be the problem but after a lot of testing, the problem seems to be >>>> coming from the MAC controller. >>>> >>>>> meson8b-dwmac c9410000.ethernet: IRQ eth_wake_irq not found >>>>> meson8b-dwmac c9410000.ethernet: IRQ eth_lpi not found >>>>> meson8b-dwmac c9410000.ethernet: PTP uses main clock >>>>> meson8b-dwmac c9410000.ethernet: User ID: 0x11, Synopsys ID: 0x37 >>>>> meson8b-dwmac c9410000.ethernet: DWMAC1000 >>>>> meson8b-dwmac c9410000.ethernet: DMA HW capability register supported >>>>> meson8b-dwmac c9410000.ethernet: RX Checksum Offload Engine supported >>>>> meson8b-dwmac c9410000.ethernet: COE Type 2 >>>>> meson8b-dwmac c9410000.ethernet: TX Checksum insertion supported >>>>> meson8b-dwmac c9410000.ethernet: Wake-Up On Lan supported >>>>> meson8b-dwmac c9410000.ethernet: Normal descriptors >>>>> meson8b-dwmac c9410000.ethernet: Ring mode enabled >>>>> meson8b-dwmac c9410000.ethernet: Enable RX Mitigation via HW Watchdog Timer >>>> >>>> The problem is not systematic. Its occurence is very random from 1/50 to >>>> 1/2. It is fairly easy to detect by setting the kernel to boot over NFS and >>>> possibly setting it to reboot automatically when reaching the prompt. >>>> >>>> When problem happens, the link is reported up by the PHY but no packet are >>>> actually going out. DHCP requests eventually times out and the kernel reset >>>> the interface. It may take several attempts but it will eventually work. >>>> >>>>> meson8b-dwmac ff3f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx >>>>> Sending DHCP requests ...... timed out! >>>>> meson8b-dwmac ff3f0000.ethernet eth0: Link is Down >>>>> IP-Config: Retrying forever (NFS root)... >>>>> meson8b-dwmac ff3f0000.ethernet eth0: PHY [0.1:08] driver [Meson G12A Internal PHY] (irq=POLL) >>>>> meson8b-dwmac ff3f0000.ethernet eth0: Register MEM_TYPE_PAGE_POOL RxQ-0 >>>>> meson8b-dwmac ff3f0000.ethernet eth0: No Safety Features support found >>>>> meson8b-dwmac ff3f0000.ethernet eth0: PTP not supported by HW >>>>> meson8b-dwmac ff3f0000.ethernet eth0: configuring for phy/rmii link mode >>>>> meson8b-dwmac ff3f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx >>>>> Sending DHCP requests ...... timed out! >>>>> meson8b-dwmac ff3f0000.ethernet eth0: Link is Down >>>>> IP-Config: Retrying forever (NFS root)... >>>>> [...] 5 retries ... >>>>> IP-Config: Retrying forever (NFS root)... >>>>> meson8b-dwmac ff3f0000.ethernet eth0: PHY [0.1:08] driver [Meson G12A Internal PHY] (irq=POLL) >>>>> meson8b-dwmac ff3f0000.ethernet eth0: Register MEM_TYPE_PAGE_POOL RxQ-0 >>>>> meson8b-dwmac ff3f0000.ethernet eth0: No Safety Features support found >>>>> meson8b-dwmac ff3f0000.ethernet eth0: PTP not supported by HW >>>>> meson8b-dwmac ff3f0000.ethernet eth0: configuring for phy/rmii link mode >>>>> meson8b-dwmac ff3f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx >>>>> Sending DHCP requests ., OK >>>>> IP-Config: Got DHCP answer from 10.1.1.1, my address is 10.1.3.229 >>>> >>>> Of course the same problem happens when not using NFS and it fairly >>>> difficult for IoT products to detect this situation and recover. >>>> >>>> The call to stmmac_mac_set() should be no-op in our case, the bits it sets >>>> have already been set by an earlier call to stmmac_mac_set(). However >>>> removing this call solves the problem. We have no idea why or what is the >>>> actual problem. >>>> >>>> Even weirder, keeping the call to stmmac_mac_set() but inserting a >>>> udelay(1) between writel() and stmmac_mac_set() solves the problem too. >>>> >>>> Suggested-by: Qi Duan <qi.duan@...ogic.com> >>>> Signed-off-by: Jerome Brunet <jbrunet@...libre.com> >>>> --- >>>> >>>> Hi, >>>> >>>> There is no intention to get this patch merged as it is. >>>> It is sent with the hope to get a better understanding of the issue >>>> and more testing. >>>> >>>> The discussion on this issue initially started on this thread >>>> https://lore.kernel.org/all/CAK4VdL3-BEBzgVXTMejrAmDjOorvoGDBZ14UFrDrKxVEMD2Zjg@mail.gmail.com/ >>>> >>>> The patches previously proposed in this thread have not solved the >>>> problem. >>>> >>>> The line removed in this patch should be a no-op when it comes to the >>>> value of MAC_CTRL_REG. So the change should make not a difference but >>>> it does. Testing result have been very good so far so there must be an >>>> unexpected consequence on the HW. I hope that someone with more >>>> knowledge on this controller will be able to shine some light on this. >>>> >>>> Cheers >>>> Jerome >>>> >>>> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 1 - >>>> 1 file changed, 1 deletion(-) >>>> >>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c >>>> index d1a7cf4567bc..3dca3cc61f39 100644 >>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c >>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c >>>> @@ -1072,7 +1072,6 @@ static void stmmac_mac_link_up(struct phylink_config *config, >>>> >>>> writel(ctrl, priv->ioaddr + MAC_CTRL_REG); >>>> >>>> - stmmac_mac_set(priv, priv->ioaddr, true); >>>> if (phy && priv->dma_cap.eee) { >>>> priv->eee_active = phy_init_eee(phy, 1) >= 0; >>>> priv->eee_enabled = stmmac_eee_init(priv); >>> >>> Now that we have a3a57bf07de2 ("net: stmmac: work around sporadic tx issue on link-up") >>> in linux-next and scheduled for stable: I will >>> >>> Jerome, can you confirm that after this commit the following is no longer needed? >>> 2c87c6f9fbdd ("net: phy: meson-gxl: improve link-up behavior") This never had any meaningful impact for me. I have already reverted it for testing. I'm all for reverting it >>> >>> Then I'd revert it, referencing the successor workaround / fix in stmmac.
Powered by blists - more mailing lists