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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 829E0C433F5 for ; Wed, 23 Mar 2022 02:27:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241344AbiCWC22 (ORCPT ); Tue, 22 Mar 2022 22:28:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241307AbiCWC2U (ORCPT ); Tue, 22 Mar 2022 22:28:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA2CD70849; Tue, 22 Mar 2022 19:26:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A5A8B614A8; Wed, 23 Mar 2022 02:26:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAC59C340F3; Wed, 23 Mar 2022 02:26:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648002410; bh=I0pEfglO0yt0xCKf2wZmloRgsww6wV2diAt8iOVavzk=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=UqDZT02mq2UVYAxkEODaMI7jLFRlVDRq2NZ53Z5b3DcpqNKSzyYHqI3y9UW0mRwq2 gY+ZaA6HvhmsNUyGhcKkulP/G8DHWBVEFVFLQRKs8qTDadV2f1wg1yxEvRHl7e4ZWP JNiU5GnCUDp0hy7fwdlohqfpL1CP/0QfZd9JBFTjGyLIbXc1JNuYYJ8dvSUQNVcFk9 kI8XexkuIIb5Ptkr7pNl5A3pVA+DyzGs16BM4EVqYfH/vmjnC3kMks3ZlDb/e3yAqd vib8vTzlroMRYgS63ey5NTCPJ7zfOvCwCB8tVh6hjj4mZ0VbI+Fn1EOLLhVrKfslC0 CJbj9AiTN+UkA== Date: Tue, 22 Mar 2022 21:26:48 -0500 From: Bjorn Helgaas To: linux-pci@vger.kernel.org Cc: Andy Shevchenko , linux-kernel@vger.kernel.org, Mick Lorain , Alex Williamson , Thomas Gleixner , Bjorn Helgaas Subject: Re: [PATCH] PCI: Avoid broken MSI on SB600 USB devices Message-ID: <20220323022648.GA1243295@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220321183446.1108325-1-helgaas@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 21, 2022 at 01:34:46PM -0500, Bjorn Helgaas wrote: > From: Bjorn Helgaas > > Some ATI SB600 USB adapters advertise MSI, but if INTx is disabled by > setting PCI_COMMAND_INTX_DISABLE, MSI doesn't work either. The PCI/PCIe > specs do not require software to set PCI_COMMAND_INTX_DISABLE when enabling > MSI, but Linux has done that for many years. > > Mick reported that 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI > devices") broke these devices. Prior to 306c54d0edb6, they used INTx. > Starting with 306c54d0edb6, they use MSI, and and the fact that Linux sets > PCI_COMMAND_INTX_DISABLE means both INTx and MSI are disabled on these > devices. > > Avoid this SB600 defect by disabling MSI so we use INTx as before. > > Fixes: 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI devices") > Link: https://bugzilla.kernel.org/show_bug.cgi?id=215690 > Link: https://lore.kernel.org/all/PxIByDyBRcsbpcmVhGSNDFAoUcMmb78ctXCkw6fbpx25TGlCHvA6SJjjFkNr1FfQZMntYPTNyvEnblxzAZ8a6jP9ddLpKeCN6Chi_2FuexU=@protonmail.com/ > BugLink: https://lore.kernel.org/all/20200702143045.23429-1-andriy.shevchenko@linux.intel.com/ > Link: https://lore.kernel.org/r/20220314101448.90074-1-andriy.shevchenko@linux.intel.com > Reported-by: Mick Lorain > Signed-off-by: Bjorn Helgaas Unless there's objection, I plan to include this in the v5.18 pull request in the next few days. It was in the 20220322 linux-next tree: https://lore.kernel.org/linux-next/20220322203829.2bb0166c@canb.auug.org.au/ > --- > drivers/pci/quirks.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index d2dd6a6cda60..5f46fed01e6c 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -1811,6 +1811,18 @@ static void quirk_alder_ioapic(struct pci_dev *pdev) > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_EESSC, quirk_alder_ioapic); > #endif > > +static void quirk_no_msi(struct pci_dev *dev) > +{ > + pci_info(dev, "avoiding MSI to work around a hardware defect\n"); > + dev->no_msi = 1; > +} > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4386, quirk_no_msi); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4387, quirk_no_msi); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4388, quirk_no_msi); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4389, quirk_no_msi); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x438a, quirk_no_msi); > +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x438b, quirk_no_msi); > + > static void quirk_pcie_mch(struct pci_dev *pdev) > { > pdev->no_msi = 1; > -- > 2.25.1 >