From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D82237D137 for ; Tue, 19 May 2026 06:09:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779170999; cv=none; b=f+CRzYxVWckCkufuJBL2Qbwtn7Sw27JVLZk0hEVnGf7VgPuKepovhFJUqMRh3sLBx1BtaqJx53p4oTEbfFvJZqMRRxhISVG+WQ6HCGoCe8hXt8jxg4MkUeToTlSFMT9+mfu/bhqyFfTtvGYBp+SDLPKndE1gTtQIU0Qoq9JxZ18= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779170999; c=relaxed/simple; bh=m4Wkj+rk/VrvijEitrfIMERd/zmOQp580t2sTN8465o=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=PYelJ8q1v0KWZ8IzTVoBr1C5cmFgwBNDvEJG2L0dxAmPMgdjhkm2Es64250GN8FyF+JoKoeXG+G9facrdHOVuHyxaZvz0l0nz6gLLA0Y5aXFfwXzdOk4sFE2RbcYH2W4zvmvQpyLWCdy36EKUQMcPbk2oNSj+3rESbgJHpUxpwc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=efLuJxH1; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="efLuJxH1" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-2ba0fc8b1f0so19766955ad.3 for ; Mon, 18 May 2026 23:09:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1779170989; x=1779775789; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=35UEgwPy5bOt7bPAiRN5I3s053dsTnr88mncjkP29bU=; b=efLuJxH10cUg1gukP013S367aaVA1L9r0LkGaWAVp/yFbTxJ2TP1CpIdBJRtmKc7Zz fGr7acFJmVz5GxgIuhls2Ti5nrnLFnmdbNxu+U8MiTjG2340f+N8rtD0C+ORScuGf5fK hCZb9/EcPOD5K+ZtqOdRkHvV587n4Br791Cdgdu3UitFLqS65nBs1VdeweVNFnSThA2d zMClp/ExjcF0ttlXzJu3T7zrjsNhRUH/xOr9AStU8oREjyuclsfyqX6fpgRU5wjPp0KQ lkJRVbYXOll1EqyHKTNG5HrGAvTPDZDFMfmXqk0omxWngJpQQi/lWN0Wm8wRackSO2rm XSTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779170989; x=1779775789; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=35UEgwPy5bOt7bPAiRN5I3s053dsTnr88mncjkP29bU=; b=Oaqic1p38wdZ7eQAlinKE7JiIIofpfudpwbBiUphNKY0Yd7E+1RKaNEO7KBqqjdspY eODBLjn/bPWcSGmxwyl/JUzpqJLohzC+stcNxF2sa7qZ93I3ZcyfQtUFjwFKVJxeJsek FC0raXj7ZGaMODogyRzp80GSvO0e29UCRRx4bTp0F/6lQEQYrDLVeKY5oTs4DXHDehfe 80UH83KRKoSBgfGF42oSKrRCuolfgBhdlAzJthAb8LljZleJk8mPO3jfXe5P2dQVfp2j 1CENaKNL+1SLy7aXSGrLE1XOUcYnM1fPhQLh3UaxxI5xY178yYVPAvj5/HGijvKP4SKo hcdQ== X-Forwarded-Encrypted: i=1; AFNElJ9U4MeO3qQpAgVYbXyLWpFD/dx9iYENkL+UiMiNHg+4gYwQha6PeZlvn0WQZtRITh3k1U1d1by9II8=@vger.kernel.org X-Gm-Message-State: AOJu0YyiPYaEEIatQBvf/FHun+xf/BemraNYp5jTVYk+sbGC081dnHuv IIx0DPWZwRS1+Q0ssjdRAAX33vBur+o1XqIIWjszDn7UV91I9EwK/cnC X-Gm-Gg: Acq92OHbnbS00umuSBYIPSw0R7u7vFPvl6ZO8AfStPB0WH3a2BBMCJVnceHFXTqopsO SUdHcdeN04m2TXeTekVPiJsdDYDmBFv/eci2YVofrmZrENZn6hkon9qFg8vlGAqD+uoCFzyU0Ek s4ZwS29vvC1+aZqBjX0iSDbPjRVRagyS4bUZMHdqIvbcpzAeoEIuKWrydXtrozbLEE350mwEEkY dnWkT8tu2mADhbdSEMB6SPOjYi0L+wHRxiqHe60F4eInQUS2/903PRJSN8DW+Y6flA1lWhE+Dkg dD++3sT60PPZdWkBHmXyjaPx3phhk0PYGXp1ldKvi73ZLq7JKgGMM1iIPkyOPprAIj8d8Mzan5W S6zV73Uks1GddBzm+a3jY5yoskOgSUGsFJRlf5obGVgYADAKm6xXynEKU0wjYMOA3HfFE5FO3rl wTWzHQrgPwfn5v/UPq3EgOhV1uWbFQ93sY126DZr7GYX5cOstTkF0ACNRCGTuJ6Ewddg== X-Received: by 2002:a17:903:284:b0:2b0:60db:7927 with SMTP id d9443c01a7336-2bd7e977b8fmr200540165ad.28.1779170989314; Mon, 18 May 2026 23:09:49 -0700 (PDT) Received: from harvey.lan (c-73-83-32-130.hsd1.wa.comcast.net. [73.83.32.130]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2bd5cfe64a9sm172805975ad.53.2026.05.18.23.09.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 May 2026 23:09:48 -0700 (PDT) From: Jim Broadus To: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Cc: peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca, Jim Broadus Subject: [PATCH] tpm: tpm_tis: Add optional delay after relinquish Date: Mon, 18 May 2026 23:09:26 -0700 Message-ID: <20260519060926.103727-1-jbroadus@gmail.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Some TPMs fail to grant locality when requested immediately after being relinquished. In this case, the TPM_ACCESS_REQUEST_USE bit of the TPM_ACCESS register is cleared immediately without setting TPM_ACCESS_ACTIVE_LOCALITY. This issue can be seen at boot since tpm_chip_start, called right after locality is relinquished, fails. This causes the probe to fail: tpm_tis MSFT0101:00: probe with driver tpm_tis failed with error -1 This occurs on some older Dell Latitudes and maybe others. To work around this, add a "settle" boolean param to tpm_tis. When this is enabled, a delay is added after locality is relinquished. Signed-off-by: Jim Broadus --- Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ drivers/char/tpm/tpm_tis.c | 7 +++++++ drivers/char/tpm/tpm_tis_core.c | 3 +++ drivers/char/tpm/tpm_tis_core.h | 1 + 4 files changed, 18 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 4d0f545fb3ec..5b7111033fbb 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -7651,6 +7651,13 @@ Kernel parameters defined by Trusted Computing Group (TCG) see https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/ + tpm_tis.settle= [HW,TPM] + Format: + When enabled, this adds a delay after locality is + relinquished. Some TPMs will fail to grant locality if + requested immediately after being relinquished. This + causes the probe to fail. + tp_printk [FTRACE] Have the tracepoints sent to printk as well as the tracing ring buffer. This is useful for early boot up diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index 9aa230a63616..8ac0ea78570e 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -101,6 +101,10 @@ module_param(force, bool, 0444); MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry"); #endif +static bool settle; +module_param(settle, bool, 0444); +MODULE_PARM_DESC(settle, "Add settle time after relinquish"); + #if defined(CONFIG_PNP) && defined(CONFIG_ACPI) static int has_hid(struct acpi_device *dev, const char *hid) { @@ -242,6 +246,9 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info) if (itpm || is_itpm(ACPI_COMPANION(dev))) set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags); + if (settle) + set_bit(TPM_TIS_SETTLE_AFTER_RELINQUISH, &phy->priv.flags); + return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg, ACPI_HANDLE(dev)); } diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 21d79ad3b164..68be26fa5817 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -184,6 +184,9 @@ static int tpm_tis_relinquish_locality(struct tpm_chip *chip, int l) __tpm_tis_relinquish_locality(priv, l); mutex_unlock(&priv->locality_count_mutex); + if (test_bit(TPM_TIS_SETTLE_AFTER_RELINQUISH, &priv->flags)) + tpm_msleep(TPM_TIMEOUT); + return 0; } diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 6c3aa480396b..413cac5e0f31 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -90,6 +90,7 @@ enum tpm_tis_flags { TPM_TIS_DEFAULT_CANCELLATION = 2, TPM_TIS_IRQ_TESTED = 3, TPM_TIS_STATUS_VALID_RETRY = 4, + TPM_TIS_SETTLE_AFTER_RELINQUISH = 5, }; struct tpm_tis_data { -- 2.54.0