kernel/Documentation, branch linux-6.6.y

ASoC: dt-bindings: asahi-kasei,ak5558: Fix the supply names

2026-03-04T12:20:29Z

commit 80ca113671a005430207d351cb403c1637106212 upstream. In the original txt format binding document ak4458.txt, the supply names are 'AVDD-supply', 'DVDD-supply', and they are also used in driver. But in the commit converting to yaml format, they are changed to 'avdd-supply', 'dvdd-supply'. After search all the dts file, these names 'AVDD-supply', 'DVDD-supply', 'avdd-supply', 'dvdd-supply' are not used in any dts file. So it is safe to fix the yaml binding document. Fixes: 829d78e3ea32 ("ASoC: dt-bindings: ak5558: Convert to dtschema") Cc: stable@vger.kernel.org Signed-off-by: Shengjiu Wang Reviewed-by: Krzysztof Kozlowski Link: https://patch.msgid.link/20260212021829.3244736-4-shengjiu.wang@nxp.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

ASoC: dt-bindings: asahi-kasei,ak4458: Fix the supply names

2026-03-04T12:20:29Z

commit e570a5ca307f6d7a6acd080fc219db2ce3c0737b upstream. In the original txt format binding document ak4458.txt, the supply names are 'AVDD-supply', 'DVDD-supply', and they are also used in driver. But in the commit converting to yaml format, they are changed to 'avdd-supply', 'dvdd-supply'. After search all the dts file, these names 'AVDD-supply', 'DVDD-supply', 'avdd-supply', 'dvdd-supply' are not used in any dts file. So it is safe to fix this yaml binding document. Fixes: 009e83b591dd ("ASoC: dt-bindings: ak4458: Convert to dtschema") Cc: stable@vger.kernel.org Signed-off-by: Shengjiu Wang Reviewed-by: Krzysztof Kozlowski Link: https://patch.msgid.link/20260212021829.3244736-3-shengjiu.wang@nxp.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

ASoC: dt-bindings: asahi-kasei,ak4458: set unevaluatedProperties:false

2026-03-04T12:20:29Z

commit 50a634f1d795721ce68583c78ba493f1d7aa8bc2 upstream. When including the dai-common.yaml, and allow '#sound-dai-cells' and "sound-name-prefix' to be used, should use unevaluatedProperties:false according to writing-bindings.rst. Fixes: 8d7de4a014f5 ("ASoC: dt-bindings: asahi-kasei,ak4458: Reference common DAI properties") Cc: stable@vger.kernel.org Signed-off-by: Shengjiu Wang Reviewed-by: Krzysztof Kozlowski Link: https://patch.msgid.link/20260212021829.3244736-2-shengjiu.wang@nxp.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

tcp: Set pingpong threshold via sysctl

2026-03-04T12:20:22Z

[ Upstream commit 562b1fdf061bff9394ccd884456ed1173c224fdc ] TCP pingpong threshold is 1 by default. But some applications, like SQL DB may prefer a higher pingpong threshold to activate delayed acks in quick ack mode for better performance. The pingpong threshold and related code were changed to 3 in the year 2019 in: commit 4a41f453bedf ("tcp: change pingpong threshold to 3") And reverted to 1 in the year 2022 in: commit 4d8f24eeedc5 ("Revert "tcp: change pingpong threshold to 3"") There is no single value that fits all applications. Add net.ipv4.tcp_pingpong_thresh sysctl tunable, so it can be tuned for optimal performance based on the application needs. Signed-off-by: Haiyang Zhang Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Acked-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/1697056244-21888-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Jakub Kicinski Stable-dep-of: 87b08913a9ae ("inet: move icmp_global_{credit,stamp} to a separate cache line") Signed-off-by: Sasha Levin

tcp: defer regular ACK while processing socket backlog

2026-03-04T12:20:22Z

[ Upstream commit 133c4c0d37175f510a10fa9bed51e223936073fc ] This idea came after a particular workload requested the quickack attribute set on routes, and a performance drop was noticed for large bulk transfers. For high throughput flows, it is best to use one cpu running the user thread issuing socket system calls, and a separate cpu to process incoming packets from BH context. (With TSO/GRO, bottleneck is usually the 'user' cpu) Problem is the user thread can spend a lot of time while holding the socket lock, forcing BH handler to queue most of incoming packets in the socket backlog. Whenever the user thread releases the socket lock, it must first process all accumulated packets in the backlog, potentially adding latency spikes. Due to flood mitigation, having too many packets in the backlog increases chance of unexpected drops. Backlog processing unfortunately shifts a fair amount of cpu cycles from the BH cpu to the 'user' cpu, thus reducing max throughput. This patch takes advantage of the backlog processing, and the fact that ACK are mostly cumulative. The idea is to detect we are in the backlog processing and defer all eligible ACK into a single one, sent from tcp_release_cb(). This saves cpu cycles on both sides, and network resources. Performance of a single TCP flow on a 200Gbit NIC: - Throughput is increased by 20% (100Gbit -> 120Gbit). - Number of generated ACK per second shrinks from 240,000 to 40,000. - Number of backlog drops per second shrinks from 230 to 0. Benchmark context: - Regular netperf TCP_STREAM (no zerocopy) - Intel(R) Xeon(R) Platinum 8481C (Saphire Rapids) - MAX_SKB_FRAGS = 17 (~60KB per GRO packet) This feature is guarded by a new sysctl, and enabled by default: /proc/sys/net/ipv4/tcp_backlog_ack_defer Signed-off-by: Eric Dumazet Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Acked-by: Soheil Hassas Yeganeh Acked-by: Dave Taht Signed-off-by: Paolo Abeni Stable-dep-of: 87b08913a9ae ("inet: move icmp_global_{credit,stamp} to a separate cache line") Signed-off-by: Sasha Levin

octeon_ep: support Octeon CN10K devices

2026-03-04T12:19:55Z

[ Upstream commit 0807dc76f3bf500f9a22465eedd2290da7357efb ] Add PCI Endpoint NIC support for Octeon CN10K devices. CN10K devices are part of Octeon 10 family products with similar PCI NIC characteristics. These include: - CN10KA - CNF10KA - CNF10KB - CN10KB Update supported device list in Documentation Signed-off-by: Shinas Rasheed Link: https://lore.kernel.org/r/20231117103817.2468176-1-srasheed@marvell.com Signed-off-by: Paolo Abeni Stable-dep-of: 73e6ffa37ceb ("octeon_ep: disable per ring interrupts") Signed-off-by: Sasha Levin

Documentation: tracing: Add PCI tracepoint documentation

2026-03-04T12:19:43Z

[ Upstream commit 8236fc613d44e59f6736d6c3e9efffaf26ab7f00 ] The PCI tracing system provides tracepoints to monitor critical hardware events that can impact system performance and reliability. Add documentation about it. Signed-off-by: Shuai Xue [bhelgaas: squash fixes: https://lore.kernel.org/r/20260108013956.14351-2-bagasdotme@gmail.com https://lore.kernel.org/r/20260108013956.14351-3-bagasdotme@gmail.com] Signed-off-by: Bjorn Helgaas Reviewed-by: Ilpo Järvinen Link: https://patch.msgid.link/20251210132907.58799-4-xueshuai@linux.alibaba.com Signed-off-by: Sasha Levin

Documentation: trace: Refactor toctree

2026-03-04T12:19:43Z

[ Upstream commit f0ba72e65516d1d86f40c79a49c4ba01c9555592 ] Refactor table of contents of kernel tracing subsystem docs to improve clarity, structure, and organization: - Reformat sections and add appropriate headings - Improve section grouping and refine descriptions for each group - Add docs intro paragraph Signed-off-by: Purva Yeshi Link: https://lore.kernel.org/r/20250318113230.24950-2-purvayeshi550@gmail.com [Bagas: massage commit message and address reviews] Co-developed-by: Bagas Sanjaya Signed-off-by: Bagas Sanjaya Acked-by: Steven Rostedt (Google) Signed-off-by: Jonathan Corbet Stable-dep-of: 8236fc613d44 ("Documentation: tracing: Add PCI tracepoint documentation") Signed-off-by: Sasha Levin

docs: fix WARNING document not included in any toctree

2026-03-04T12:19:43Z

[ Upstream commit 998bece1d22bf2cbc819cb3a492148932d4e12a8 ] Add debugging.rst to the relevant toctree to fix warning about missing documentation inclusion in toctree. Signed-off-by: SurajSonawane2415 Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20241002195817.22972-1-surajsonawane0215@gmail.com Stable-dep-of: 8236fc613d44 ("Documentation: tracing: Add PCI tracepoint documentation") Signed-off-by: Sasha Levin

Documentation: tracing: Add ring-buffer mapping

2026-03-04T12:19:43Z

[ Upstream commit a1e0dd7ce38af3fb1a3bc54a222a7c5e4eaa4202 ] It is now possible to mmap() a ring-buffer to stream its content. Add some documentation and a code example. Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-5-vdonnefort@google.com Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt (Google) Stable-dep-of: 8236fc613d44 ("Documentation: tracing: Add PCI tracepoint documentation") Signed-off-by: Sasha Levin