From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C4071CEE35A for ; Tue, 18 Nov 2025 21:43:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=v1dJwLQv+S3QSj+rpqiUebkM3raOf7UsXODt7xXlwo0=; b=EJB80cScE/Yt5h K9znbj8CR3CnTJ9YDawPRdzq5Sglf9uY1aVLNNJAWTrDKaMNsaSVMGwXP2iqmoCQ75B/+rQuWkaio n0+G4MLGVI5KVfloVub7dcjlFwzShgz75ogk5YtgrtJWknb6iBlWOp4SuNXNMD9meCzemv++GzEXa od77yfWzmnkrSgWlZ54Orr0PSPM8nvYOaaO7Yuy41oz/Jh41cCIqEYLnG61EItl9+/z8vpX61i5qX 5O6sHmel8pDEpj8P7silsYQLzEmHQIPEyXh9Elbvvy+belqjA4WoF8fc4fd9XKtUIGnZ3mbnYDkHG GnU9C2JMkt4VBfcA449w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLTTw-000000018Od-1JQw; Tue, 18 Nov 2025 21:43:24 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLTTv-000000018NO-0Vq8; Tue, 18 Nov 2025 21:43:23 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id D4BD2601DE; Tue, 18 Nov 2025 21:43:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23EFAC4AF0D; Tue, 18 Nov 2025 21:43:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763502200; bh=lAnQCrSiM3uixg2a7WEWN3009GHh2tQrWsx3N4gBtcc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=haVaC/s/JZOhkHQI72Lcu18JKJ/MHz01UjYRxBF3i5UKPVmqofXy8DZsr8hoyCTst BJ0+mm2Ipp8FUsWT8S63gsOqsUGPoV1tjZ0JgGkv42BU6XwJ2L0wuc6bGG6tDr36Ef ktOvLsay7YWfLqsmwQFNGxmjUYWhxcLG3i8er2yDHKHQva+Zb2IrDO+pZwbYsgMjQQ dsv2j5J0HOA/89jT7GgeFgDo4LzFVGSAmKA07ALuoABKDu6F6/glCX7jRj4XyT38Px yXjDsNLJ1idZY1EguY/CKMB4eJSKzDUOOFUsMwveEJaghCUU1d63K/P7Dm255knTUE Fg8cXlPHmSwEw== From: Bjorn Helgaas To: Niklas Cassel , Shawn Lin Cc: Manivannan Sadhasivam , Lorenzo Pieralisi , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Rob Herring , Heiko Stuebner , Kever Yang , Simon Xue , Damien Le Moal , Dragan Simic , FUKAUMI Naoki , Diederik de Haas , Richard Zhu , Frank Li , Lucas Stach , Shawn Guo , Sascha Hauer , Fabio Estevam , Conor Dooley , Krzysztof Kozlowski , Thierry Reding , Jonathan Hunter , Hans Zhang , linux-tegra@vger.kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, kernel@pengutronix.de, Bjorn Helgaas Subject: [PATCH v2 1/4] PCI: dwc: Advertise L1 PM Substates only if driver requests it Date: Tue, 18 Nov 2025 15:42:15 -0600 Message-ID: <20251118214312.2598220-2-helgaas@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251118214312.2598220-1-helgaas@kernel.org> References: <20251118214312.2598220-1-helgaas@kernel.org> MIME-Version: 1.0 X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org From: Bjorn Helgaas L1 PM Substates require the CLKREQ# signal and may also require device-specific support. If CLKREQ# is not supported or driver support is lacking, enabling L1.1 or L1.2 may cause errors when accessing devices, e.g., nvme nvme0: controller is down; will reset: CSTS=0xffffffff, PCI_STATUS=0x10 If the kernel is built with CONFIG_PCIEASPM_POWER_SUPERSAVE=y or users enable L1.x via sysfs, users may trip over these errors even if L1 Substates haven't been enabled by firmware or the driver. To prevent such errors, disable advertising the L1 PM Substates unless the driver sets "dw_pcie.l1ss_support" to indicate that it knows CLKREQ# is present and any device-specific configuration has been done. Set "dw_pcie.l1ss_support" in tegra194 (if DT includes the "supports-clkreq' property) and qcom (for cfg_2_7_0, cfg_1_9_0, cfg_1_34_0, and cfg_sc8280xp controllers) so they can continue to use L1 Substates. Based on Niklas's patch: https://patch.msgid.link/20251017163252.598812-2-cassel@kernel.org Signed-off-by: Bjorn Helgaas --- .../pci/controller/dwc/pcie-designware-ep.c | 2 ++ .../pci/controller/dwc/pcie-designware-host.c | 2 ++ drivers/pci/controller/dwc/pcie-designware.c | 24 +++++++++++++++++++ drivers/pci/controller/dwc/pcie-designware.h | 2 ++ drivers/pci/controller/dwc/pcie-qcom.c | 2 ++ drivers/pci/controller/dwc/pcie-tegra194.c | 3 +++ 6 files changed, 35 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c index 7f2112c2fb21..ad6c0fd67a65 100644 --- a/drivers/pci/controller/dwc/pcie-designware-ep.c +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c @@ -966,6 +966,8 @@ int dw_pcie_ep_init_registers(struct dw_pcie_ep *ep) if (ep->ops->init) ep->ops->init(ep); + dw_pcie_hide_unsupported_l1ss(pci); + ptm_cap_base = dw_pcie_find_ext_capability(pci, PCI_EXT_CAP_ID_PTM); /* diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 20c9333bcb1c..7abeb771e32d 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -1060,6 +1060,8 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp) PCI_COMMAND_MASTER | PCI_COMMAND_SERR; dw_pcie_writel_dbi(pci, PCI_COMMAND, val); + dw_pcie_hide_unsupported_l1ss(pci); + dw_pcie_config_presets(pp); /* * If the platform provides its own child bus config accesses, it means diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index c644216995f6..6e6a0dac5b53 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -1081,6 +1081,30 @@ void dw_pcie_edma_remove(struct dw_pcie *pci) dw_edma_remove(&pci->edma); } +void dw_pcie_hide_unsupported_l1ss(struct dw_pcie *pci) +{ + u16 l1ss; + u32 l1ss_cap; + + if (pci->l1ss_support) + return; + + l1ss = dw_pcie_find_ext_capability(pci, PCI_EXT_CAP_ID_L1SS); + if (!l1ss) + return; + + /* + * Unless the driver claims "l1ss_support", don't advertise L1 PM + * Substates because they require CLKREQ# and possibly other + * device-specific configuration. + */ + l1ss_cap = dw_pcie_readl_dbi(pci, l1ss + PCI_L1SS_CAP); + l1ss_cap &= ~(PCI_L1SS_CAP_PCIPM_L1_1 | PCI_L1SS_CAP_ASPM_L1_1 | + PCI_L1SS_CAP_PCIPM_L1_2 | PCI_L1SS_CAP_ASPM_L1_2 | + PCI_L1SS_CAP_L1_PM_SS); + dw_pcie_writel_dbi(pci, l1ss + PCI_L1SS_CAP, l1ss_cap); +} + void dw_pcie_setup(struct dw_pcie *pci) { u32 val; diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index e995f692a1ec..a68eea47d451 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -516,6 +516,7 @@ struct dw_pcie { int max_link_speed; u8 n_fts[2]; struct dw_edma_chip edma; + bool l1ss_support; /* L1 PM Substates support */ struct clk_bulk_data app_clks[DW_PCIE_NUM_APP_CLKS]; struct clk_bulk_data core_clks[DW_PCIE_NUM_CORE_CLKS]; struct reset_control_bulk_data app_rsts[DW_PCIE_NUM_APP_RSTS]; @@ -573,6 +574,7 @@ int dw_pcie_prog_ep_inbound_atu(struct dw_pcie *pci, u8 func_no, int index, int type, u64 parent_bus_addr, u8 bar, size_t size); void dw_pcie_disable_atu(struct dw_pcie *pci, u32 dir, int index); +void dw_pcie_hide_unsupported_l1ss(struct dw_pcie *pci); void dw_pcie_setup(struct dw_pcie *pci); void dw_pcie_iatu_detect(struct dw_pcie *pci); int dw_pcie_edma_detect(struct dw_pcie *pci); diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 805edbbfe7eb..61c2f4e2f74d 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -1067,6 +1067,8 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie) val &= ~REQ_NOT_ENTR_L1; writel(val, pcie->parf + PARF_PM_CTRL); + pci->l1ss_support = true; + val = readl(pcie->parf + PARF_AXI_MSTR_WR_ADDR_HALT_V2); val |= EN; writel(val, pcie->parf + PARF_AXI_MSTR_WR_ADDR_HALT_V2); diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c index 10e74458e667..3934757baa30 100644 --- a/drivers/pci/controller/dwc/pcie-tegra194.c +++ b/drivers/pci/controller/dwc/pcie-tegra194.c @@ -703,6 +703,9 @@ static void init_host_aspm(struct tegra_pcie_dw *pcie) val |= (pcie->aspm_pwr_on_t << 19); dw_pcie_writel_dbi(pci, pcie->cfg_link_cap_l1sub, val); + if (pcie->supports_clkreq) + pci->l1ss_support = true; + /* Program L0s and L1 entrance latencies */ val = dw_pcie_readl_dbi(pci, PCIE_PORT_AFR); val &= ~PORT_AFR_L0S_ENTRANCE_LAT_MASK; -- 2.43.0 _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip