From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F0552253F2; Thu, 12 Dec 2024 15:48:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734018532; cv=none; b=oxQf8+e90XgjAET87/SKyD3CUPDXLLbgjpJsXg3rJ1J13yujC6vkbeH6eIIPJc8VrMwjXh7kkWOTccfWKHBeOUGuSNuhtFgEHM3AgXI5Shwl1ATLL0cIoSpvAvY4p0JCI6Lugy/XLIfdbQIokcpO84F9cllYIwi8rv4KDsTRu9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734018532; c=relaxed/simple; bh=H/h4RnoW2KCzSnKSrHosiLGZ+13jt+u4YUTiN0RpuBY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GMVaXzRNERREordfml/W3xSk3S2DC73pAPWv7puVVFnLviYNDGwDMUBZs3AKU007AouUntrAXGSOBRj2PqqZo8BX/z7DzDJu3+YuLJfPFxubuj/4MDSdV4AXju5+4zrWJnY+MCVK1A9im454dj1MYzdJmOpN0rYzd7obGD6mISc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SOtF9MiO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SOtF9MiO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69A89C4CED0; Thu, 12 Dec 2024 15:48:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734018531; bh=H/h4RnoW2KCzSnKSrHosiLGZ+13jt+u4YUTiN0RpuBY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SOtF9MiO87V2J+dmS/W/hjFh+A4DWGt80MPelxSbQWG13Ff0llEE8EJGlgeAz+KkC QZJjULcSJAo55FwqYRhoxdpIrj8x+N6vcV6oby0Lk0gfw5Kfzii2S27mJo4rNNXXMx uRpD8nZ7lLUGwSQKcPz43hayC7sUuyiGoZf2qeLM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jian-Hong Pan , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Bjorn Helgaas , Kuppuswamy Sathyanarayanan , Sasha Levin Subject: [PATCH 6.6 292/356] PCI: vmd: Set devices to D0 before enabling PM L1 Substates Date: Thu, 12 Dec 2024 16:00:11 +0100 Message-ID: <20241212144256.107324003@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241212144244.601729511@linuxfoundation.org> References: <20241212144244.601729511@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jian-Hong Pan [ Upstream commit d66041063192497a4a97d21dbf86b79a03a7f4fb ] The remapped PCIe Root Port and the child device have PM L1 Substates capability, but they are disabled originally. Here is a failed example on ASUS B1400CEAE: Capabilities: [900 v1] L1 PM Substates L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1- ASPM_L1.2+ ASPM_L1.1- L1_PM_Substates+ PortCommonModeRestoreTime=32us PortTPowerOnTime=10us L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2+ ASPM_L1.1- T_CommonMode=0us LTR1.2_Threshold=101376ns L1SubCtl2: T_PwrOn=50us Enable PCI-PM L1 PM Substates for devices below VMD while they are in D0 (see PCIe r6.0, sec 5.5.4). Link: https://lore.kernel.org/r/20241001083438.10070-4-jhp@endlessos.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=218394 Signed-off-by: Jian-Hong Pan Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas Reviewed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Sasha Levin --- drivers/pci/controller/vmd.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index ade18991e7366..992fea22fd9f8 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -751,11 +751,9 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) if (!(features & VMD_FEAT_BIOS_PM_QUIRK)) return 0; - pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); - pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR); if (!pos) - return 0; + goto out_state_change; /* * Skip if the max snoop LTR is non-zero, indicating BIOS has set it @@ -763,7 +761,7 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) */ pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, <r_reg); if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK))) - return 0; + goto out_state_change; /* * Set the default values to the maximum required by the platform to @@ -775,6 +773,13 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata) pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg); pci_info(pdev, "VMD: Default LTR value set by driver\n"); +out_state_change: + /* + * Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per + * PCIe r6.0, sec 5.5.4. + */ + pci_set_power_state_locked(pdev, PCI_D0); + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL); return 0; } -- 2.43.0