From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760689AbbIECik (ORCPT ); Fri, 4 Sep 2015 22:38:40 -0400 Received: from mail-pa0-f44.google.com ([209.85.220.44]:33288 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750953AbbIECib (ORCPT ); Fri, 4 Sep 2015 22:38:31 -0400 Message-ID: <55EA55A5.3030606@gmail.com> Date: Fri, 04 Sep 2015 19:38:29 -0700 From: Frank Rowand Reply-To: frowand.list@gmail.com User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: David Daney CC: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Rob Herring , Grant Likely , David Daney Subject: Re: [PATCH] of_pci_irq: Silence bogus "of_irq_parse_pci() failed ..." messages. References: <1441393926-23225-1-git-send-email-ddaney.cavm@gmail.com> <55EA41E3.5010103@gmail.com> <55EA480C.6090306@gmail.com> In-Reply-To: <55EA480C.6090306@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/4/2015 6:40 PM, David Daney wrote: > On 09/04/2015 06:14 PM, Frank Rowand wrote: >> On 9/4/2015 12:12 PM, David Daney wrote: >>> From: David Daney >>> >>> It is perfectly legitimate for a PCI device to have an >>> PCI_INTERRUPT_PIN value of zero. This happens if the device doesn't >>> use interrupts, or on PCIe devices, where only MSI/MSI-X are >>> supported. >>> >>> Silence the annoying "of_irq_parse_pci() failed with rc=-19" error >>> messages by making them conditional on !-ENODEV (which can only be >>> produced in the PCI_INTERRUPT_PIN == 0 case). >>> >>> Signed-off-by: David Daney >>> --- >>> drivers/of/of_pci_irq.c | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/of/of_pci_irq.c b/drivers/of/of_pci_irq.c >>> index 1710d9d..33d242a 100644 >>> --- a/drivers/of/of_pci_irq.c >>> +++ b/drivers/of/of_pci_irq.c >>> @@ -106,7 +106,9 @@ int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) >>> >>> ret = of_irq_parse_pci(dev, &oirq); >>> if (ret) { >>> - dev_err(&dev->dev, "of_irq_parse_pci() failed with rc=%d\n", ret); >>> + if (ret != -ENODEV) >>> + dev_err(&dev->dev, >>> + "of_irq_parse_pci() failed with rc=%d\n", ret); >>> return 0; /* Proper return code 0 == NO_IRQ */ >>> } >>> >>> >> >> It is not safe to assume that the functions that of_irq_parse_pci() calls >> will never be modified to return -ENODEV, thus resulting in of_irq_parse_pci() >> returning -ENODEV for a reason other than PCI_INTERRUPT_PIN == 0. >> > > Since the current implementation *only ever* returns -ENODEV for PCI_INTERRUPT_PIN == 0, we could just document that behavior, and not hack up the APIs by adding a second return channel from the function. And for each function that of_irq_parse_pci() calls and returns status from the function call you would need to document that behavior, and so on recursively. For example, you would need to document of_irq_parse_one(). And that returns status from more function calls, so you would need to document of_irq_parse_oldworld(), of_parse_phandle_with_args(), of_irq_parse_raw(), and then anything they call. > > The additional change on top of my patch would be to add a comment describing this behavior. > > David Daney. < snip > -Frank