--- title: Linux 7.3 Will Begin Checking USB-C Cables For Alt-Mode... description: Linux 7.3 introduces kernel-level checking of USB-C cable capabilities for alt-mode support, addressing a long-standing gap where the kernel didn't verify... canonical: https://daily.dev/posts/linux-7-3-will-begin-checking-usb-c-cables-for-alt-mode-support-qysrvgpsu twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Linux 7.3 Will Begin Checking USB-C Cables For Alt-Mode Support | daily.dev og:description: Linux 7.3 introduces kernel-level checking of USB-C cable capabilities for alt-mode support, addressing a long-standing gap where the kernel didn't verify... og:url: https://daily.dev/posts/linux-7-3-will-begin-checking-usb-c-cables-for-alt-mode-support-qysrvgpsu og:image: https://api.daily.dev/og/posts/qYsrVGpsu.png og:image:alt: Linux 7.3 Will Begin Checking USB-C Cables For Alt-Mode Support og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Linux 7.3 Will Begin Checking USB-C Cables For Alt-Mode Support **[Phoronix](https://daily.dev/sources/phoronix)** · 2 min read · 0 upvotes · 0 comments ## Summary Linux 7.3 introduces kernel-level checking of USB-C cable capabilities for alt-mode support, addressing a long-standing gap where the kernel didn't verify whether a cable actually supports alt-modes like DisplayPort or Thunderbolt. The new code checks for an identity header, whether a passive cable is limited to USB 2.0 speeds, and that active cables have matching plugs, preventing incorrectly advertised states or initialization failures. Contributed by Andrei Kuchynski of Google's ChromeOS team. Separately, the release adds a busy_poll option for USB4STREAM (introduced in Linux 7.2 by Intel) to reduce latency for USB4/Thunderbolt data transfers at the cost of higher CPU usage. Other changes include Device Tree bindings for the ASpeed AST2700 DWC3 controller. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What changed in the Linux kernel's USB-C cable handling in version 7.3? Linux 7.3 adds kernel-level checking of USB-C cable capabilities for alternate mode support, such as DisplayPort and Thunderbolt. Previously the kernel did not verify these capabilities, which could lead to incorrectly advertised state configurations or initialization failures when trying to engage alt-modes with an unsupported cable. The new code checks the identity header, passive cable USB 2.0 speed limits, and plug correspondence for active cables. It was contributed by Andrei Kuchynski of Google's ChromeOS team. _Track kernel-level hardware changes like this USB-C update by following Linux release notes on daily.dev._ ### What does the busy_poll option do for USB4STREAM in Linux 7.3? Enabling busy_poll with USB4STREAM in Linux 7.3 provides lower latency data transfers between USB4 or Thunderbolt-connected systems, at the cost of increased CPU activity. USB4STREAM itself was originally added by Intel in Linux 7.2 for sending data packets between USB4-connected systems, and the busy_poll option builds on that feature. _Developers tuning USB4 throughput versus CPU usage can follow kernel latency features via daily.dev._ ## Similar posts on daily.dev - [USB Driver For Google Tensor SoCs, UCSI Thunderbolt Alt Mode In Linux 7.0](https://daily.dev/posts/usb-driver-for-google-tensor-socs-ucsi-thunderbolt-alt-mode-in-linux-7-0-l9ab6ul24) · Phoronix · 0 upvotes · 0 comments - [A New Linux Driver Could Make USB4 Cables a Blazing Fast Way to Move Data](https://daily.dev/posts/a-new-linux-driver-could-make-usb4-cables-a-blazing-fast-way-to-move-data-vmnsnowa3) · It's Foss · 7 upvotes · 0 comments - [Many USB Improvements & New Hardware Merged For Linux 7.1](https://daily.dev/posts/many-usb-improvements-new-hardware-merged-for-linux-7-1-l0wflpqfx) · Phoronix · 0 upvotes · 0 comments --- Tags: [#linux](https://daily.dev/tags/linux) [View this post on daily.dev](https://daily.dev/posts/linux-7-3-will-begin-checking-usb-c-cables-for-alt-mode-support-qysrvgpsu) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Linux 7.3 Will Begin Checking USB-C Cables For Alt-Mode Support","url":"https://daily.dev/posts/linux-7-3-will-begin-checking-usb-c-cables-for-alt-mode-support-qysrvgpsu","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/linux-7-3-will-begin-checking-usb-c-cables-for-alt-mode-support-qysrvgpsu"},"datePublished":"2026-08-28T10:17:27.557Z","dateModified":"2026-08-28T10:17:55.356Z","description":"Linux 7.3 introduces kernel-level checking of USB-C cable capabilities for alt-mode support, addressing a long-standing gap where the kernel didn't verify...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a46036e97362b73fd674849db0f1da09?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a46036e97362b73fd674849db0f1da09?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Phoronix","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Phoronix","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/6a26ba379dd64932830aa0c9803dd7ee","url":"https://daily.dev/sources/phoronix"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/linux-7-3-will-begin-checking-usb-c-cables-for-alt-mode-support-qysrvgpsu","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"linux","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Phoronix","item":"https://daily.dev/sources/phoronix"},{"@type":"ListItem","position":3,"name":"Linux 7.3 Will Begin Checking USB-C Cables For Alt-Mode Support"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/linux-7-3-will-begin-checking-usb-c-cables-for-alt-mode-support-qysrvgpsu#faq","mainEntity":[{"@type":"Question","name":"What changed in the Linux kernel's USB-C cable handling in version 7.3?","acceptedAnswer":{"@type":"Answer","text":"Linux 7.3 adds kernel-level checking of USB-C cable capabilities for alternate mode support, such as DisplayPort and Thunderbolt. Previously the kernel did not verify these capabilities, which could lead to incorrectly advertised state configurations or initialization failures when trying to engage alt-modes with an unsupported cable. The new code checks the identity header, passive cable USB 2.0 speed limits, and plug correspondence for active cables. It was contributed by Andrei Kuchynski of Google's ChromeOS team. Track kernel-level hardware changes like this USB-C update by following Linux release notes on daily.dev."}},{"@type":"Question","name":"What does the busy_poll option do for USB4STREAM in Linux 7.3?","acceptedAnswer":{"@type":"Answer","text":"Enabling busy_poll with USB4STREAM in Linux 7.3 provides lower latency data transfers between USB4 or Thunderbolt-connected systems, at the cost of increased CPU activity. USB4STREAM itself was originally added by Intel in Linux 7.2 for sending data packets between USB4-connected systems, and the busy_poll option builds on that feature. Developers tuning USB4 throughput versus CPU usage can follow kernel latency features via daily.dev."}}]} ```