From nobody Fri Apr 17 19:37:40 2026 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4fy4sd0xbSz6WwXZ for ; Fri, 17 Apr 2026 19:37:41 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R12" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4fy4sc73p3z44pt for ; Fri, 17 Apr 2026 19:37:40 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1776454661; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=VawBEbvb9+XfENIHJFn6bgcHhsjfUSz8w89BpvJqCyE=; b=aHFe0toNWWHVBTQIYzIcJEi1JeDbmU9w9srGYbwWeBf9eMrAuFb+2qeSebt58PqPik58cu zB44hWDFnc0Pk24nMUEDD5K/QgypXcYhB90KANFATDvy9hSERktxbefuzxM5+coNGvZdrt yXJZJdd3D/e9WjSdgzmJCbJKZNBt+MXzCtU9nFVkOB8AP4mAWtxzA+Crvl7rBFJjgJ7ggv /XZ6Adr7i+qb9IBKGTm00Fvr0tuUrGU3eIpGheUXTb5hYVnCYD0JIF5YxjeIuNnZ1jolbL 778CtgB8bBC/sVaAx7ZVGyf8T2YcpGftOXgTqwoLHTFKofS1d+TqPbtZgYHHMA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1776454661; a=rsa-sha256; cv=none; b=TJTPJ1TmxYI2NLhi7TaJQZD90y/ZihyDjIgE/AhAkjOn3MNe3QQTca/Js611tUQJrxbtjl kqZT5QK2tmG55k2mMu2oJfGp2JXbtl86pXl2rG3ijtB4MYnPgdD/ZTqMLstVdIw0os/Gdx 82n/3sPQTlMDSnAo9cLkwVWmT9iElLhXmJ/ScN2vczreKSp/kZQQ8oOxFd4PPWIj2XzPHr +zbiSKGbfaqp0A1GK+/8BUd/P2GnRzcoRTiRTGyfJ7l2fSu3R6wg1rAxU9GXmLBfb87R4/ gjsA43ReZ7lOOQI/XUjh5kmRSV/2rMr2ao3gWScXbr8uy1/Bwe5KnsRqW3XC0A== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1776454661; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=VawBEbvb9+XfENIHJFn6bgcHhsjfUSz8w89BpvJqCyE=; b=v3+MctyPDo/O6Un31jxCo1+m5saAbR2OOXSZMZ+UGwp5OD0i5KUPyM3M9un78ivoErsqnD nH9GMQM0rU0g8SWmu5TqfLl0AezMggTbSmARXrH5ppEyGYh0ENEM7yIsfK4jjHS1tUH+vl 6mTiLUYdjO9xCveG14sFQzJQj68n/jL678W+P4mmaVXN/wm36VdHHM67GemqqAoO42Ly86 wTRU9ejggiqL6QXKGVAKJgp/nHFgA/KQTqeU9Osu3lM6EahyRa77fcOTrcKKmM/01VOdWJ scF5PpjEC5XcZo6Dfe1NlN2goDjOkECIhshYYvsg7ircq5qLe6pp7nLqHgBt5A== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4fy4sc6Fj6z16kB for ; Fri, 17 Apr 2026 19:37:40 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 1bb57 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Fri, 17 Apr 2026 19:37:40 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Roger Pau =?utf-8?Q?Monn=C3=A9?= Subject: git: 45c8ddc874bb - main - uart/pci: recover ADL AMT device after FIFO size probing List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: royger X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 45c8ddc874bb9149ed20cb46b6ef8bdd0567714c Auto-Submitted: auto-generated Date: Fri, 17 Apr 2026 19:37:40 +0000 Message-Id: <69e28c04.1bb57.42d4783d@gitrepo.freebsd.org> The branch main has been updated by royger: URL: https://cgit.FreeBSD.org/src/commit/?id=45c8ddc874bb9149ed20cb46b6ef8bdd0567714c commit 45c8ddc874bb9149ed20cb46b6ef8bdd0567714c Author: Roger Pau Monné AuthorDate: 2026-03-27 09:55:02 +0000 Commit: Roger Pau Monné CommitDate: 2026-04-17 19:37:26 +0000 uart/pci: recover ADL AMT device after FIFO size probing When the Alder Lake Serial-over-LAN device is put into loopback mode and repeated writes are performed to the data register it results in the device ending up in a non-functional state afterwards. Recovering the device to a working state requires re-writing the LCR register with it's current value (no effective change). This should be harmless on all other devices. Sponsored by: Citrix Systems R&D Differential revision: https://reviews.freebsd.org/D56107 Reviewed by: imp --- sys/dev/uart/uart_dev_ns8250.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/sys/dev/uart/uart_dev_ns8250.c b/sys/dev/uart/uart_dev_ns8250.c index b0c7cd4b44e1..c13eabe9055e 100644 --- a/sys/dev/uart/uart_dev_ns8250.c +++ b/sys/dev/uart/uart_dev_ns8250.c @@ -999,6 +999,15 @@ ns8250_bus_probe(struct uart_softc *sc) uart_setreg(bas, REG_IER, ier); uart_setreg(bas, REG_MCR, mcr); uart_setreg(bas, REG_FCR, 0); + /* + * The Alder Lake AMT SOL Redirection device will never + * set LSR_OE (when in loopback mode at least) and + * instead block further input by not setting LSR_TEMT. + * Recovering the device afterwards into a working + * state requires re-writing the LCR register. This + * should be harmless on all other devices. + */ + uart_setreg(bas, REG_LCR, uart_getreg(bas, REG_LCR)); uart_barrier(bas); count = 0; goto describe;