From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ilkka Koskinen <ilkka@os.amperecomputing.com>, Robin Murphy <robin.murphy@arm.com>, Will Deacon <will@kernel.org>, Sasha Levin <sashal@kernel.org>, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 6.7 08/26] perf/arm-cmn: Workaround AmpereOneX errata AC04_MESH_1 (incorrect child count) Date: Thu, 29 Feb 2024 10:48:27 -0500 [thread overview] Message-ID: <20240229154851.2849367-8-sashal@kernel.org> (raw) In-Reply-To: <20240229154851.2849367-1-sashal@kernel.org> From: Ilkka Koskinen <ilkka@os.amperecomputing.com> [ Upstream commit 50572064ec7109b00eef8880e905f55861c8b3de ] AmpereOneX mesh implementation has a bug in HN-P nodes that makes them report incorrect child count. The failing crosspoints report 8 children while they only have two. When the driver tries to access the inexistent child nodes, it believes it has reached an invalid node type and probing fails. The workaround is to ignore those incorrect child nodes and continue normally. Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com> [ rm: rewrote simpler generalised version ] Tested-by: Ilkka Koskinen <ilkka@os.amperecomputing.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/ce4b1442135fe03d0de41859b04b268c88c854a3.1707498577.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/perf/arm-cmn.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c index c584165b13bab..7e3aa7e2345fa 100644 --- a/drivers/perf/arm-cmn.c +++ b/drivers/perf/arm-cmn.c @@ -2305,6 +2305,17 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) dev_dbg(cmn->dev, "ignoring external node %llx\n", reg); continue; } + /* + * AmpereOneX erratum AC04_MESH_1 makes some XPs report a bogus + * child count larger than the number of valid child pointers. + * A child offset of 0 can only occur on CMN-600; otherwise it + * would imply the root node being its own grandchild, which + * we can safely dismiss in general. + */ + if (reg == 0 && cmn->part != PART_CMN600) { + dev_dbg(cmn->dev, "bogus child pointer?\n"); + continue; + } arm_cmn_init_node_info(cmn, reg & CMN_CHILD_NODE_ADDR, dn); -- 2.43.0
WARNING: multiple messages have this Message-ID (diff)
From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ilkka Koskinen <ilkka@os.amperecomputing.com>, Robin Murphy <robin.murphy@arm.com>, Will Deacon <will@kernel.org>, Sasha Levin <sashal@kernel.org>, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 6.7 08/26] perf/arm-cmn: Workaround AmpereOneX errata AC04_MESH_1 (incorrect child count) Date: Thu, 29 Feb 2024 10:48:27 -0500 [thread overview] Message-ID: <20240229154851.2849367-8-sashal@kernel.org> (raw) In-Reply-To: <20240229154851.2849367-1-sashal@kernel.org> From: Ilkka Koskinen <ilkka@os.amperecomputing.com> [ Upstream commit 50572064ec7109b00eef8880e905f55861c8b3de ] AmpereOneX mesh implementation has a bug in HN-P nodes that makes them report incorrect child count. The failing crosspoints report 8 children while they only have two. When the driver tries to access the inexistent child nodes, it believes it has reached an invalid node type and probing fails. The workaround is to ignore those incorrect child nodes and continue normally. Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com> [ rm: rewrote simpler generalised version ] Tested-by: Ilkka Koskinen <ilkka@os.amperecomputing.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/ce4b1442135fe03d0de41859b04b268c88c854a3.1707498577.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/perf/arm-cmn.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c index c584165b13bab..7e3aa7e2345fa 100644 --- a/drivers/perf/arm-cmn.c +++ b/drivers/perf/arm-cmn.c @@ -2305,6 +2305,17 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) dev_dbg(cmn->dev, "ignoring external node %llx\n", reg); continue; } + /* + * AmpereOneX erratum AC04_MESH_1 makes some XPs report a bogus + * child count larger than the number of valid child pointers. + * A child offset of 0 can only occur on CMN-600; otherwise it + * would imply the root node being its own grandchild, which + * we can safely dismiss in general. + */ + if (reg == 0 && cmn->part != PART_CMN600) { + dev_dbg(cmn->dev, "bogus child pointer?\n"); + continue; + } arm_cmn_init_node_info(cmn, reg & CMN_CHILD_NODE_ADDR, dn); -- 2.43.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-02-29 15:49 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-02-29 15:48 [PATCH AUTOSEL 6.7 01/26] media: Revert "media: rkisp1: Drop IRQF_SHARED" Sasha Levin 2024-02-29 15:48 ` Sasha Levin 2024-02-29 15:48 ` Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 02/26] media: rkisp1: Fix IRQ handling due to shared interrupts Sasha Levin 2024-02-29 15:48 ` Sasha Levin 2024-02-29 15:48 ` Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 03/26] Revert "drm/msm/gpu: Push gpu lock down past runpm" Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 04/26] HID: logitech-hidpp: Do not flood kernel log Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 05/26] ASoC: cs42l43: Handle error from devm_pm_runtime_enable Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 06/26] wifi: iwlwifi: mvm: use correct address 3 in A-MSDU Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 07/26] arm64: jump_label: use constraints "Si" instead of "i" Sasha Levin 2024-02-29 15:48 ` Sasha Levin 2024-02-29 15:56 ` Mark Rutland 2024-02-29 15:56 ` Mark Rutland 2024-03-18 13:24 ` Sasha Levin 2024-03-18 13:24 ` Sasha Levin 2024-02-29 15:48 ` Sasha Levin [this message] 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 08/26] perf/arm-cmn: Workaround AmpereOneX errata AC04_MESH_1 (incorrect child count) Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 09/26] btrfs: add and use helper to check if block group is used Sasha Levin 2024-02-29 15:52 ` David Sterba 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 10/26] selftests: openvswitch: Add validation for the recursion test Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 11/26] net: tls: factor out tls_*crypt_async_wait() Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 12/26] selftests: tls: use exact comparison in recv_partial Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 13/26] ASoC: rt5645: Make LattePanda board DMI match more precise Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 14/26] spi: omap2-mcspi: Revert FIFO support without DMA Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 15/26] spi: intel-pci: Add support for Lunar Lake-M SPI serial flash Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 16/26] regmap: kunit: Ensure that changed bytes are actually different Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 17/26] ASoC: amd: yc: Fix non-functional mic on Lenovo 82UU Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 18/26] x86/xen: Add some null pointer checking to smp.c Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 19/26] MIPS: Clear Cause.BD in instruction_pointer_set Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 20/26] ceph: always queue a writeback when revoking the Fb caps Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 21/26] ceph: add ceph_cap_unlink_work to fire check_caps() immediately Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 22/26] HID: multitouch: Add required quirk for Synaptics 0xcddc device Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 23/26] ASoC: SOF: ipc4-pcm: Workaround for crashed firmware on system suspend Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 24/26] ALSA: hda/realtek: cs35l41: Add internal speaker support for ASUS UM3402 with missing DSD Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 25/26] gen_compile_commands: fix invalid escape sequence warning Sasha Levin 2024-02-29 15:48 ` [PATCH AUTOSEL 6.7 26/26] arm64/sve: Lower the maximum allocation for the SVE ptrace regset Sasha Levin 2024-02-29 15:48 ` Sasha Levin
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