From nobody Fri Jun 12 16:01:47 2026 Received: from mail-dy1-f170.google.com (mail-dy1-f170.google.com [74.125.82.170]) (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 396691474CC for ; Fri, 8 May 2026 20:36:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.170 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778272607; cv=none; b=ehg9xRqshcKhcZTB/hhkHCUCD+kL7Mn4cq561yWNlN1P+Vh/+NGZtp2xF0yschFDTFTdnbS5+SvdtZt4khc4g6LvtTeq68ozyMH8p+yZAoV9ED5seek+8GMKJ41THAoV4bwfD6mwlueEc8+Xm2oZX/0G9N8AHSnHpsSJq+NzeuA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778272607; c=relaxed/simple; bh=r16uspIZznIhMXpG4T/bkzN1F3PDMKLiIzc6CunoQAE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lwffxtbFDctGIf05X59efJXfvxvkqRGTrtI2gmHRv3ftd2/inUkfTu3ilq7a0xE7bx+/NNUi/D2JeLSoSXikEVIyvYgAvR+Xw1mBVPeEhxvj1ADa7Fo6VYocUONhi7sYOURaFPWsVWbg0tg3iMw/wYufKgic1/mV8cKXw83a6E8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=JL3ZJ39o; arc=none smtp.client-ip=74.125.82.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="JL3ZJ39o" Received: by mail-dy1-f170.google.com with SMTP id 5a478bee46e88-2f3c623322bso3974263eec.0 for ; Fri, 08 May 2026 13:36:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1778272605; x=1778877405; 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=it9s5SDS+9FA8rWlzgMlowzHbZDxtLnrq7mFV1fkn1U=; b=JL3ZJ39oRHxYbgVSZMAxGm2Fke9GB4gduf9FOIT8iInsuGmpoGHU5haJKHFO/p/0Mh Vc1RyaycpOw6bzgjR5S526NrkpjLlyUNvzzNPMqVrFxQh1w+sc5M4+DfipbFOhcBD2GB CY92TQ+NNh5og8L66Pdv7vGhQ1L23Hww5opjU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778272605; x=1778877405; 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=it9s5SDS+9FA8rWlzgMlowzHbZDxtLnrq7mFV1fkn1U=; b=oDNC4UqMBEhNw4FiNMS8k24iyyA6sRyZ1GrlATgQsDTy5AGHCd9yLC05RRKXisRIW/ AOXUpOg6du5AAMs0184yuBv9ofbKLx7PMhRgW8h2sincL4FRCWEhEBJEKVqU0fkmLSp0 Ae/dY4Ba5jOWkHe+E/oFA9Fa6gVX7uDZlB+4KCtJFh8TdppYNGSurBSI2f7DlgFEVhTs L/8StTqcjJlwbYxKzydeV63iJD+fl4Kk4OiUAdgBm308QdfrzF1Miazol5YG7sHJHvEi nqoMshq8F6x2J3FG0iOMryRdCoCI3kGCJAFvvX7Y8EV1vwAnLbqmk2quIFffHkW489X4 lEhg== X-Forwarded-Encrypted: i=1; AFNElJ8oXXAg9RZI8COI8FjDBHKekdaRBe9wCCHRyHu3Tzmlh4WyjQsPHreB1tOvT1PsIw7g7DYiVwYp7E7Vq4I=@vger.kernel.org X-Gm-Message-State: AOJu0Yy3f+tBJ0504pQwBeakNKsEap/ZtcjmARJB1UatxNXBkNnHKJBn 8Jav+YC/OYRTGLNdsmoZuWNQ4pHzmzqXH+QjUNH+xWh0s3CQYfuWdXwFUkrXduHcGg== X-Gm-Gg: Acq92OGHWrz/TbWBjcn48bz2zKh0p+LS3wXdZ5/XvG7vks498cKihYvyOW5uoAKHdGA j7UjNJhOVFwo3FGg1/iMLkQ26tNpmFGhZOjCMYcJQdXw6BbujTQd+pBv7mneyuUsHtMWYoGpqDd uPAQBHuNOcDsK0Y2pggwV38e5CnapgUXh3Gp84jCVMmkVdpcJ+8rvrP/TmS8JvnxdfwmVwX/oyG OWninlCD8mdUY+cOJwFcVCgfRMhCNP5LJLoblycsgUqe/9/CxsJIWrWUseC3Wih0owx/DyyEhOX A+WLsnXXrEYPENgkGwihmK5exX/WWWkX6i1gTtyJDGQYmMvNWkcHinqTFrJfUy/++6A328z0OQe tdGgMhlBX9fO5i9L+AWslFCtUmLzpoGXnc9Vf2nkGwtT3A+v8qpAP5r2CafnHH3zM1+BeQKtSrQ ROv101Kiv7+razJil0agYZrjB0xW2672FpXRnqrJ2rrajiHxrckn5XztuV7Tnqfw== X-Received: by 2002:a05:7301:3f16:b0:2c9:1943:e7ff with SMTP id 5a478bee46e88-2f54b35fb00mr6500611eec.10.1778272605216; Fri, 08 May 2026 13:36:45 -0700 (PDT) Received: from localhost ([2a00:79e0:2e7c:8:68c8:9c69:b0fb:a687]) by smtp.gmail.com with UTF8SMTPSA id 5a478bee46e88-2f88885b820sm3683873eec.20.2026.05.08.13.36.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 08 May 2026 13:36:44 -0700 (PDT) From: Brian Norris To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Manivannan Sadhasivam , Lukas Wunner , linux-kernel@vger.kernel.org, Brian Norris Subject: [PATCH v3] PCI/portdrv: Allow probing even without child services Date: Fri, 8 May 2026 13:36:29 -0700 Message-ID: <20260508133629.v3.1.I5fd5d83f518681b3949d8ab2f16ba8244fd3e774@changeid> X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The PCIe port driver fails to probe if it finds no child services, presumably under the assumption that the driver is not useful in that case. However, the driver *can* still be useful for power management support -- namely, it still configures the port for runtime PM / D3, which may be important for allowing a bridge to enter low power modes. Thus, allow probe to succeed even if no IRQs and no child services are available. This also mirrors existing behavior for ports that have no PCIe capabilities, where we'd also probe successfully. This change is a bit more important after commit f5cd8a929c82 ("PCI: dwc: Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI controller"), because it's common for some DWC-based systems to: 1. have only have the "aer" and "pcie_pme" port services available and 2. not define legacy INTx interrupts properly in their device tree. After commit f5cd8a929c82, such systems may fail pcie_init_service_irqs() and so exit with -ENODEV. Link: https://lore.kernel.org/all/nyada24tqwlkzdceyoxbzitzygvp4elvj5oajnqdw= b33xkcdwk@76vnrx45fsfd/ Signed-off-by: Brian Norris --- I didn't get an answer to my responses to the last review feedback: https://lore.kernel.org/all/adg5IPWdCSv1UqFE@google.com/ So I've attempted to address the feedback without churning all the port service drivers. Changes in v3: * defer pci_set_master() until we really know we have some child service Changes in v2: * clear master when we have no child services drivers/pci/pcie/portdrv.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c index 2d6aa488fe7b..a79a52560849 100644 --- a/drivers/pci/pcie/portdrv.c +++ b/drivers/pci/pcie/portdrv.c @@ -330,7 +330,7 @@ static int pcie_device_init(struct pci_dev *pdev, int s= ervice, int irq) */ static int pcie_port_device_register(struct pci_dev *dev) { - int status, capabilities, i, nr_service; + int status, capabilities, i; int irqs[PCIE_PORT_DEVICE_MAXSERVICES]; =20 /* Enable PCI Express port device */ @@ -343,7 +343,6 @@ static int pcie_port_device_register(struct pci_dev *de= v) if (!capabilities) return 0; =20 - pci_set_master(dev); /* * Initialize service irqs. Don't use service devices that * require interrupts if there is no way to generate them. @@ -355,29 +354,20 @@ static int pcie_port_device_register(struct pci_dev *= dev) if (status) { capabilities &=3D PCIE_PORT_SERVICE_HP; if (!capabilities) - goto error_disable; + return 0; } =20 /* Allocate child services if any */ - status =3D -ENODEV; - nr_service =3D 0; for (i =3D 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) { int service =3D 1 << i; if (!(capabilities & service)) continue; - if (!pcie_device_init(dev, service, irqs[i])) - nr_service++; + pcie_device_init(dev, service, irqs[i]); } - if (!nr_service) - goto error_cleanup_irqs; =20 - return 0; + pci_set_master(dev); =20 -error_cleanup_irqs: - pci_free_irq_vectors(dev); -error_disable: - pci_disable_device(dev); - return status; + return 0; } =20 typedef int (*pcie_callback_t)(struct pcie_device *); --=20 2.54.0.563.g4f69b47b94-goog