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Thu, 03 Sep 2026 09:06:28 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 15480183741827357636 EX-QQ-RecipientCnt: 16 Precedence: bulk X-Mailing-List: spacemit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: multipart/signed; boundary=5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24; micalg=pgp-sha512; protocol="application/pgp-signature" Date: Thu, 03 Sep 2026 09:06:25 +0800 Message-Id: Subject: Re: [BUG] PCI: spacemit-k1: port C probe hard-hangs a CPU with one endpoint on Milk-V Jupiter From: "Troy Mitchell" To: "Alex Elder" , "Manivannan Sadhasivam" , , "Bruno Banelli" , "Troy Mitchell" Cc: , , "Yixun Lan" , "Lorenzo Pieralisi" , "Krzysztof Wilczynski" , "Rob Herring" , "Bjorn Helgaas" , "Danilo Krummrich" , "Uwe Kleine-Koenig" , "Javier Martinez Canillas" , X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260825052249.66921-1-bbanelli@gmail.com> <7a29717b-dc62-4421-b783-7b78e4375268@riscstar.com> In-Reply-To: <7a29717b-dc62-4421-b783-7b78e4375268@riscstar.com> X-QQ-SENDSIZE: 520 Feedback-ID: zesmtpgz:linux.spacemit.com:qybglogicsvrgz:qybglogicsvrgz3a-0 X-QQ-XMAILINFO: OegHrGdQ9dQUM4rcL/UVOoWjrJLz5Nzb+TUFTx9WDCS/0LAq3sT6vH3w 6AdDiFHcsZrwbamOt53PT02mSiYLUkBPQe8b/i1vkM+DAJweZ7vuGsCaxlUSnkccplSujVi v7wE4m+MjxB5f3VqTNRTS9PfvH7L745KMN1pBngIzRSxNQqQc3lJiKrybCdwhJ7ytb9ASBI SOgGJwAsFwP6S6hIve5vRGRjo9Pq/kGfU3q+zU6Z16icv301xRAD7EoeGMo5amb6nXAoS/u n3jIjX7L46pAMhuFMEOsfcmyoCy3VOZcgdrAy19t+8F2yN4L3di1y492cgD+EVUDpgq70u8 06SRwVqeCzXHOxofTq93/osYqdXEvrV0+tAoRzp7CYmtIFLkaIGLy9oH8el8r+v/B0Ih8cU e/pa0ti9LXzZedI9dL8ETMy0+ZOU618H5klM/70jVfJtERUAa3lSCW4XYAKhp6YeYNsLKnq M/Pb6AIrOph3lluQ9ZjHOy6aVbXB6/qmbp2bD3qry2t3GUmGdmhw9lm0W2+0xb0WZ2zXI1k bgHvmJKFtjvP11gLRl3pbvaUwvVAQnwZfxbOEt+YG+vbuUdOKul0rsbq4U5EvuquoMUBj/t WXSPne41/uaZ5D9ZwuOHSQpEUBSNL1JY+9HMKOknAnKppuNQ/JaQNAo39bURWmY7iadMJ9t g6EKdUhT/E9LzN3to3paW5pHSs5fv7fdDTrXAXF1vYii1UCJA/pN1hanKXv1q/zNfQ0yIJ/ GnwhIfrmLJ3L3exHyVPvSim4rHTL4VMU7Lke86wfKHJ3wfcNpCrnj+okSL4//2CRN6vBRNl ccw0SJoJNu4BM6SGVfaqB40w37Qi10rhJpZe12m3qNe/ccS62KYze3MMDCp7COAqRLha9Kh I92V3DnbZ4ag5uZkNhxLZn/GGnUg3DpV+BZrgkMpf6YJmTAH7TzBiCi7B2/3dqgQqxmlgic pkozDRFAZD3OmS2m1ftuD4X4xM2D5DEmhKewq2qm9uFGT7Ui6ypjEbgjmeFqi9CYmXSdnJW RouKzzAL2WvVMpofuyjdB/VBJuzTe3rb7CEE419g/3H6OQzw8YHV3Iir89oSr4MA411TnBg rX7p2Ae+JpDOViZCGivtFmZxG/6tZeFb3WQ7OzbZGMN X-QQ-XMRINFO: MPJ6Tf5t3I/ylTmHUqvI8+Wpn+Gzalws3A== X-QQ-RECHKSPAM: 0 --5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 On Wed Sep 2, 2026 at 9:56 PM +08, Alex Elder wrote: > On 9/2/26 8:42 AM, Manivannan Sadhasivam wrote: >> On Tue, Aug 25, 2026 at 07:22:49AM +0200, Bruno Banelli wrote: >>> Hi, >>> >>> On a Milk-V Jupiter, probing the PCIe controller at ca800000 (port C, t= he >>> card slot) permanently wedges the CPU that runs the probe when one >>> particular add-in card is installed. The CPU stops responding to NMI, = and >>> because the probe is asynchronous, kernel_init() then blocks forever in >>> async_synchronize_full() and the machine never finishes booting. >>> >>> The same card, in the same slot, on the same board, does *not* hang the >>> vendor 6.6 kernel -- it reports "Phy link never came up" and boots norm= ally. >>> Six other cards do not hang mainline either. So whatever the electrica= l >>> cause, this looks like a robustness problem in pcie-spacemit-k1: an end= point >>> should not be able to hang a host-side DBI register access. >>> >>> >>> HARDWARE >>> -------- >>> Milk-V Jupiter v1.1, SpacemiT M1 (socinfo: CPU[M1-8571] REV[C] DRO[1= 30]), >>> 16 GiB LPDDR4X. >>> Firmware: stock vendor U-Boot 2022.10 (k1-bl-v2.2.9), unmodified. >>> Port B (ca400000, M.2) has a Samsung PM9B1 NVMe and works throughout= . >>> Port C (ca800000) is the card slot -- an x8-length connector, silksc= reened >>> PCIE_X2, wired x2. >>> >>> >>> REPRODUCED ON >>> ------------- >>> v7.1 and v7.2, riscv defconfig (plus PHY_SPACEMIT_K1_USB2, USB_DWC3, >>> SPACEMIT_K1_TSENSOR, IGB, IGC, NVMe/ext4 built in). >>> gcc 13.3.0 (cross) and gcc 16.2.0 (native, Debian sid). >>> Identical failure in all combinations. Not a regression -- port C h= as >>> never worked with this card on mainline. >>> >>> Command line: >>> console=3DttyS0,115200 earlycon root=3D/dev/nvme0n1p2 rootwait rw >>> swiotlb=3D65536 clk_ignore_unused pd_ignore_unused >>> >>> >>> SYMPTOM >>> ------- >>> Port C prints its address ranges and then never speaks again. (Log bel= ow is >>> from a run with port B disabled in DT, so nothing is interleaved.) >>> >>> [ 1.290074] spacemit-k1-pcie ca800000.pcie: host bridge /soc/pcie-bu= s/pcie@ca800000 ranges: >>> [ 1.297283] spacemit-k1-pcie ca800000.pcie: IO 0x00b7002000..0= x00b7101fff -> 0x0000000000 >>> [ 1.312783] spacemit-k1-pcie ca800000.pcie: MEM 0x00a0000000..0= x00afffffff -> 0x00a0000000 >>> [ 1.326753] spacemit-k1-pcie ca800000.pcie: MEM 0x00b0000000..0= x00b6ffffff -> 0x00b0000000 >>> [22.348490] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: >>> [22.351764] rcu: 4-...0: (12 GPs behind) idle=3D051c/1/0x4000000= 000000000 softirq=3D43/43 fqs=3D1908 >>> [22.367040] Sending NMI from CPU 2 to CPUs 4: >>> [32.367049] After 10 seconds, these CPUS still haven't responded to = the NMI: 4 >>> >>> The CPU ignoring an NMI for ten seconds is why I read this as an MMIO a= ccess >>> that never receives a completion rather than a spin or a deadlock. >>> >>> >>> LOCALISATION >>> ------------ >>> I added a dev_info() before each step of k1_pcie_init() (patch at the e= nd of >>> this mail). The last marker port C prints is the one immediately befor= e the >>> first DBI access: >>> >>> [1.347050] spacemit-k1-pcie ca800000.pcie: K1DBG 1 toggle_soft_reset >>> [1.362635] spacemit-k1-pcie ca800000.pcie: K1DBG 2 enable_resources >>> [1.370918] spacemit-k1-pcie ca800000.pcie: K1DBG 3 first DBI write (= vendor/device ID) >>> >>=20 >> Sounds weird that an endpoint is causing DBI write hang. >>=20 >> Can Alex or someone from Spacemit look into this issue? > > I think Yixun Lan or maybe Troy Mitchell should investigate. > > I have not done anything on the Milk-V Jupiter and have no > access to any board of that type. This seems to be device-specific. Some of our team members are already look= ing into it. --=20 Troy Mitchell --5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iIMEABYKACsWIQSL4Ay2cExaPXAQcU2YCe+A+TM0LwUCapjIEQ0caUB0cm95LXku b3JnAAoJEJgJ74D5MzQv/3sA/3cB2V5ShRbpFKlrOGG/ak5AYZnPZSI4Cj9mD/S8 v+bfAP9TR48gN2ZQ6yxgPavM/EQxD9OF1y6BdJfsu6pnp6BtAA== =unDq -----END PGP SIGNATURE----- --5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B05E8C61DD6 for ; Thu, 3 Sep 2026 01:07:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; 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Thu, 03 Sep 2026 01:07:29 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.spacemit.com; s=mxsw2412; t=1788397598; bh=sn4Zqvuy3iv8MXIhtE8ntlyyLJ+J0+s0jH6g+E8SxjY=; h=Mime-Version:Date:Message-Id:Subject:From:To; b=A5k5NRBvPhC3tGJXsyYf7fc8LdYv7Vuxkx/RmhmEDP1YRrBswZjX99/MkSV9suFTc QdM3Cvr2jl9mqvuSmqB9povPoTwKDjNEdKUqPctGTWLSuGls4LEq5Enpb5xHyN+tQS NudzFTF8nwnPxqGUIb/8AmVmt3DENtCar8MEF/04= X-QQ-mid: zesmtpgz6t1788397590t809805a0 X-QQ-Originating-IP: VhXi++IEq6mjKwdvVbXNY7Td/lOsJov/j5KV2ygThxU= Received: from = ( [120.237.158.181]) by bizesmtp.qq.com (ESMTP) with id ; Thu, 03 Sep 2026 09:06:28 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 15480183741827357636 EX-QQ-RecipientCnt: 16 Mime-Version: 1.0 Date: Thu, 03 Sep 2026 09:06:25 +0800 Message-Id: Subject: Re: [BUG] PCI: spacemit-k1: port C probe hard-hangs a CPU with one endpoint on Milk-V Jupiter From: "Troy Mitchell" To: "Alex Elder" , "Manivannan Sadhasivam" , , "Bruno Banelli" , "Troy Mitchell" Cc: , , "Yixun Lan" , "Lorenzo Pieralisi" , "Krzysztof Wilczynski" , "Rob Herring" , "Bjorn Helgaas" , "Danilo Krummrich" , "Uwe Kleine-Koenig" , "Javier Martinez Canillas" , X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260825052249.66921-1-bbanelli@gmail.com> <7a29717b-dc62-4421-b783-7b78e4375268@riscstar.com> In-Reply-To: <7a29717b-dc62-4421-b783-7b78e4375268@riscstar.com> X-QQ-SENDSIZE: 520 Feedback-ID: zesmtpgz:linux.spacemit.com:qybglogicsvrgz:qybglogicsvrgz3a-0 X-QQ-XMAILINFO: Nj+N5zFEdFN5ecwz1dKKsurGbo40lil/pAtYzExiD4CbPnsFd6P0Yf3U BmoAOPWMMwfzkRy86Pa9g/Ff+G2KHWmscKrzo9ToPkGk2Scp2MtxPvbJqWARlUQVWWmzOqQ WiX3e/sxkUPtKHWaKCoHgE2sIpi5ikh4JhZu4ITX8+EqqBsZYnEWhVvPfq+dZZC+G5k6ycL a1wW03EPUxUAsD1yL+kBE2NB3v5y2lZi4gY9jfqOasX9TNZZKyLhA0xNAVAFTrSYanCKRgL evxutO3ujhh9KMWuf0m1/0puqSXtOi1vQS3CcVTqCssbSxb4sD3dZZQMDaRkEba13X9wPL9 qKVhOrPpDZcxe61I0UvENwWb8OVOAKf1692Rqq0oQER5nIFyfPb22gqPCHf60NOmaZbG+mm KWmplHFmg2kAiZDCyu8byB1rgOrIY2s5HGrj6xf3lscXDR8x2DA+9rLORexHhHK2tlYu0zA uiJR49fU/fxH7zFInMDcilIhsnH9msQppH8npuNe6Lfjq4b1nPRhr2+MDCK3c6STDOFjkzd mFxdWr8DcYX33WUIbR6QkGL6652GyzCS2AdCqdBqTK0VpQZ4mqVIDPZiKFpDVhNpyrb9LBh 3IhTa+GoKuuzdvWmf6D89rsZq+mjCoFExBEEMknK0MAF5su53VNopKDnHMvS8XRxl1PQdY0 4S6axfg6jst67SUXpCYWtKV4tWWkYfRUKc0vxH3jyALJ3X0mXFXNbniQzW24KZoBIxMrYA4 EVdD9TcCM/7wFOARHbcNy9tMR464eiFVnbh3HNGsdRMOGrREmfkWek6RXbgd9cywGQFfoik /Z6oFqGoVRn9cCl1fM/ka1hhuHNJXL2F5NJhmuB8v7OS/47gdbTQTskUKErgoZau0tXjSRY oTMrxIYiepBRHLWENdxk96ipjsBldLzzHswZyAGZo8sFlLnZlI5naZlPXld2dOlkEmsMZJj EXf5Lk8HAGKq3j10PANcYMRoL9LS3NecESVCrVfVA0XzNlvy1wKL7tvsKZo/HohRA/4U24X Sn+MRylOL2dEeKV6tN1Z8rlvmafOq/G2GgPnUsHiHipE/NElgLiWhecHnZRMQzwOxzxefAb i2HQeCGj9PyTBeMf+HjsyBx6O05IdGmiaA/yGBO8s0O X-QQ-XMRINFO: Nq+8W0+stu50tPAe92KXseR0ZZmBTk3gLg== X-QQ-RECHKSPAM: 0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260902_180727_245162_C30AFB49 X-CRM114-Status: GOOD ( 14.76 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============3165887725231524269==" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org --===============3165887725231524269== Content-Type: multipart/signed; boundary=5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24; micalg=pgp-sha512; protocol="application/pgp-signature" --5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 On Wed Sep 2, 2026 at 9:56 PM +08, Alex Elder wrote: > On 9/2/26 8:42 AM, Manivannan Sadhasivam wrote: >> On Tue, Aug 25, 2026 at 07:22:49AM +0200, Bruno Banelli wrote: >>> Hi, >>> >>> On a Milk-V Jupiter, probing the PCIe controller at ca800000 (port C, t= he >>> card slot) permanently wedges the CPU that runs the probe when one >>> particular add-in card is installed. The CPU stops responding to NMI, = and >>> because the probe is asynchronous, kernel_init() then blocks forever in >>> async_synchronize_full() and the machine never finishes booting. >>> >>> The same card, in the same slot, on the same board, does *not* hang the >>> vendor 6.6 kernel -- it reports "Phy link never came up" and boots norm= ally. >>> Six other cards do not hang mainline either. So whatever the electrica= l >>> cause, this looks like a robustness problem in pcie-spacemit-k1: an end= point >>> should not be able to hang a host-side DBI register access. >>> >>> >>> HARDWARE >>> -------- >>> Milk-V Jupiter v1.1, SpacemiT M1 (socinfo: CPU[M1-8571] REV[C] DRO[1= 30]), >>> 16 GiB LPDDR4X. >>> Firmware: stock vendor U-Boot 2022.10 (k1-bl-v2.2.9), unmodified. >>> Port B (ca400000, M.2) has a Samsung PM9B1 NVMe and works throughout= . >>> Port C (ca800000) is the card slot -- an x8-length connector, silksc= reened >>> PCIE_X2, wired x2. >>> >>> >>> REPRODUCED ON >>> ------------- >>> v7.1 and v7.2, riscv defconfig (plus PHY_SPACEMIT_K1_USB2, USB_DWC3, >>> SPACEMIT_K1_TSENSOR, IGB, IGC, NVMe/ext4 built in). >>> gcc 13.3.0 (cross) and gcc 16.2.0 (native, Debian sid). >>> Identical failure in all combinations. Not a regression -- port C h= as >>> never worked with this card on mainline. >>> >>> Command line: >>> console=3DttyS0,115200 earlycon root=3D/dev/nvme0n1p2 rootwait rw >>> swiotlb=3D65536 clk_ignore_unused pd_ignore_unused >>> >>> >>> SYMPTOM >>> ------- >>> Port C prints its address ranges and then never speaks again. (Log bel= ow is >>> from a run with port B disabled in DT, so nothing is interleaved.) >>> >>> [ 1.290074] spacemit-k1-pcie ca800000.pcie: host bridge /soc/pcie-bu= s/pcie@ca800000 ranges: >>> [ 1.297283] spacemit-k1-pcie ca800000.pcie: IO 0x00b7002000..0= x00b7101fff -> 0x0000000000 >>> [ 1.312783] spacemit-k1-pcie ca800000.pcie: MEM 0x00a0000000..0= x00afffffff -> 0x00a0000000 >>> [ 1.326753] spacemit-k1-pcie ca800000.pcie: MEM 0x00b0000000..0= x00b6ffffff -> 0x00b0000000 >>> [22.348490] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: >>> [22.351764] rcu: 4-...0: (12 GPs behind) idle=3D051c/1/0x4000000= 000000000 softirq=3D43/43 fqs=3D1908 >>> [22.367040] Sending NMI from CPU 2 to CPUs 4: >>> [32.367049] After 10 seconds, these CPUS still haven't responded to = the NMI: 4 >>> >>> The CPU ignoring an NMI for ten seconds is why I read this as an MMIO a= ccess >>> that never receives a completion rather than a spin or a deadlock. >>> >>> >>> LOCALISATION >>> ------------ >>> I added a dev_info() before each step of k1_pcie_init() (patch at the e= nd of >>> this mail). The last marker port C prints is the one immediately befor= e the >>> first DBI access: >>> >>> [1.347050] spacemit-k1-pcie ca800000.pcie: K1DBG 1 toggle_soft_reset >>> [1.362635] spacemit-k1-pcie ca800000.pcie: K1DBG 2 enable_resources >>> [1.370918] spacemit-k1-pcie ca800000.pcie: K1DBG 3 first DBI write (= vendor/device ID) >>> >>=20 >> Sounds weird that an endpoint is causing DBI write hang. >>=20 >> Can Alex or someone from Spacemit look into this issue? > > I think Yixun Lan or maybe Troy Mitchell should investigate. > > I have not done anything on the Milk-V Jupiter and have no > access to any board of that type. This seems to be device-specific. Some of our team members are already look= ing into it. --=20 Troy Mitchell --5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iIMEABYKACsWIQSL4Ay2cExaPXAQcU2YCe+A+TM0LwUCapjIEQ0caUB0cm95LXku b3JnAAoJEJgJ74D5MzQv/3sA/3cB2V5ShRbpFKlrOGG/ak5AYZnPZSI4Cj9mD/S8 v+bfAP9TR48gN2ZQ6yxgPavM/EQxD9OF1y6BdJfsu6pnp6BtAA== =unDq -----END PGP SIGNATURE----- --5aa6fa5638c6e4ef04b289541629de5e53ccc8327148dde49673ae679c24-- --===============3165887725231524269== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv --===============3165887725231524269==--