From nobody Fri Jun 19 18:20:27 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95AF5C433EF for ; Thu, 31 Mar 2022 07:12:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232083AbiCaHO0 (ORCPT ); Thu, 31 Mar 2022 03:14:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231809AbiCaHNm (ORCPT ); Thu, 31 Mar 2022 03:13:42 -0400 Received: from angie.orcam.me.uk (angie.orcam.me.uk [78.133.224.34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6DBD8C6802; Thu, 31 Mar 2022 00:11:34 -0700 (PDT) Received: by angie.orcam.me.uk (Postfix, from userid 500) id 8C5749200B3; Thu, 31 Mar 2022 09:11:33 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 87D9192009B; Thu, 31 Mar 2022 08:11:33 +0100 (BST) Date: Thu, 31 Mar 2022 08:11:33 +0100 (BST) From: "Maciej W. Rozycki" To: Greg Kroah-Hartman , Jiri Slaby cc: Andy Shevchenko , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] serial: 8250: Report which option to enable for blacklisted PCI devices Message-ID: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Provide information in the kernel log as to what configuration option to=20 enable for PCI UART devices that have been blacklisted in the generic=20 PCI 8250 UART driver and which have a dedicated driver available to=20 handle that has been disabled. The rationale is there is no easy way=20 for the user to map a specific PCI vendor:device pair to an individual=20 dedicated driver while the generic driver has this information readily=20 available and it will likely be confusing that the generic driver does=20 not register such a port. This is unlike usual drivers, such as drivers/net/ethernet/3com/3c59x.c=20 which handles all the hardware family members regardless of differences=20 between them, and following an existing example where a serio driver=20 provides suggestions as to the correct configuration options to use: psmouse serio1: synaptics: The touchpad can support a better bus than the t= oo old PS/2 protocol. Make sure MOUSE_PS2_SYNAPTICS_SMBUS and RMI4_SMB are = enabled to get a better touchpad experience. A message is then printed like: serial 0000:04:00.3: ignoring port, enable SERIAL_8250_PERICOM to handle when an affected device is encountered and the generic driver rejects it. Signed-off-by: Maciej W. Rozycki --- Changes from v2: - Include examples of current practices in the change description so as to=20 give a better justification. Changes from v1: - Add missing filler struct member initialisers for PCI_DEVICE entries. --- drivers/tty/serial/8250/8250_pci.c | 67 ++++++++++++++++++++++----------= ----- 1 file changed, 40 insertions(+), 27 deletions(-) linux-serial-8250-pci-blacklist-config.diff Index: linux-macro/drivers/tty/serial/8250/8250_pci.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- linux-macro.orig/drivers/tty/serial/8250/8250_pci.c +++ linux-macro/drivers/tty/serial/8250/8250_pci.c @@ -3518,6 +3518,12 @@ static struct pciserial_board pci_boards }, }; =20 +#define REPORT_CONFIG(option) \ + (IS_ENABLED(CONFIG_##option) ? 0 : (kernel_ulong_t)&#option) +#define REPORT_8250_CONFIG(option) \ + (IS_ENABLED(CONFIG_SERIAL_8250_##option) ? \ + 0 : (kernel_ulong_t)&"SERIAL_8250_"#option) + static const struct pci_device_id blacklist[] =3D { /* softmodems */ { PCI_VDEVICE(AL, 0x5457), }, /* ALi Corporation M5457 AC'97 Modem */ @@ -3525,40 +3531,43 @@ static const struct pci_device_id blackl { PCI_DEVICE(0x1543, 0x3052), }, /* Si3052-based modem, default IDs */ =20 /* multi-io cards handled by parport_serial */ - { PCI_DEVICE(0x4348, 0x7053), }, /* WCH CH353 2S1P */ - { PCI_DEVICE(0x4348, 0x5053), }, /* WCH CH353 1S1P */ - { PCI_DEVICE(0x1c00, 0x3250), }, /* WCH CH382 2S1P */ + /* WCH CH353 2S1P */ + { PCI_DEVICE(0x4348, 0x7053), 0, 0, REPORT_CONFIG(PARPORT_SERIAL), }, + /* WCH CH353 1S1P */ + { PCI_DEVICE(0x4348, 0x5053), 0, 0, REPORT_CONFIG(PARPORT_SERIAL), }, + /* WCH CH382 2S1P */ + { PCI_DEVICE(0x1c00, 0x3250), 0, 0, REPORT_CONFIG(PARPORT_SERIAL), }, =20 /* Intel platforms with MID UART */ - { PCI_VDEVICE(INTEL, 0x081b), }, - { PCI_VDEVICE(INTEL, 0x081c), }, - { PCI_VDEVICE(INTEL, 0x081d), }, - { PCI_VDEVICE(INTEL, 0x1191), }, - { PCI_VDEVICE(INTEL, 0x18d8), }, - { PCI_VDEVICE(INTEL, 0x19d8), }, + { PCI_VDEVICE(INTEL, 0x081b), REPORT_8250_CONFIG(MID), }, + { PCI_VDEVICE(INTEL, 0x081c), REPORT_8250_CONFIG(MID), }, + { PCI_VDEVICE(INTEL, 0x081d), REPORT_8250_CONFIG(MID), }, + { PCI_VDEVICE(INTEL, 0x1191), REPORT_8250_CONFIG(MID), }, + { PCI_VDEVICE(INTEL, 0x18d8), REPORT_8250_CONFIG(MID), }, + { PCI_VDEVICE(INTEL, 0x19d8), REPORT_8250_CONFIG(MID), }, =20 /* Intel platforms with DesignWare UART */ - { PCI_VDEVICE(INTEL, 0x0936), }, - { PCI_VDEVICE(INTEL, 0x0f0a), }, - { PCI_VDEVICE(INTEL, 0x0f0c), }, - { PCI_VDEVICE(INTEL, 0x228a), }, - { PCI_VDEVICE(INTEL, 0x228c), }, - { PCI_VDEVICE(INTEL, 0x4b96), }, - { PCI_VDEVICE(INTEL, 0x4b97), }, - { PCI_VDEVICE(INTEL, 0x4b98), }, - { PCI_VDEVICE(INTEL, 0x4b99), }, - { PCI_VDEVICE(INTEL, 0x4b9a), }, - { PCI_VDEVICE(INTEL, 0x4b9b), }, - { PCI_VDEVICE(INTEL, 0x9ce3), }, - { PCI_VDEVICE(INTEL, 0x9ce4), }, + { PCI_VDEVICE(INTEL, 0x0936), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x0f0a), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x0f0c), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x228a), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x228c), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x4b96), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x4b97), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x4b98), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x4b99), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x4b9a), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x4b9b), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x9ce3), REPORT_8250_CONFIG(LPSS), }, + { PCI_VDEVICE(INTEL, 0x9ce4), REPORT_8250_CONFIG(LPSS), }, =20 /* Exar devices */ - { PCI_VDEVICE(EXAR, PCI_ANY_ID), }, - { PCI_VDEVICE(COMMTECH, PCI_ANY_ID), }, + { PCI_VDEVICE(EXAR, PCI_ANY_ID), REPORT_8250_CONFIG(EXAR), }, + { PCI_VDEVICE(COMMTECH, PCI_ANY_ID), REPORT_8250_CONFIG(EXAR), }, =20 /* Pericom devices */ - { PCI_VDEVICE(PERICOM, PCI_ANY_ID), }, - { PCI_VDEVICE(ACCESSIO, PCI_ANY_ID), }, + { PCI_VDEVICE(PERICOM, PCI_ANY_ID), REPORT_8250_CONFIG(PERICOM), }, + { PCI_VDEVICE(ACCESSIO, PCI_ANY_ID), REPORT_8250_CONFIG(PERICOM), }, =20 /* End of the black list */ { } @@ -3840,8 +3849,12 @@ pciserial_init_one(struct pci_dev *dev, board =3D &pci_boards[ent->driver_data]; =20 exclude =3D pci_match_id(blacklist, dev); - if (exclude) + if (exclude) { + if (exclude->driver_data) + pci_warn(dev, "ignoring port, enable %s to handle\n", + (const char *)exclude->driver_data); return -ENODEV; + } =20 rc =3D pcim_enable_device(dev); pci_save_state(dev);