From patchwork Tue Jun 9 09:14:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Piotr Stankiewicz X-Patchwork-Id: 11594951 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6C489159A for ; Tue, 9 Jun 2020 09:15:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C0F420812 for ; Tue, 9 Jun 2020 09:15:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728206AbgFIJPa (ORCPT ); Tue, 9 Jun 2020 05:15:30 -0400 Received: from mga01.intel.com ([192.55.52.88]:19611 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726187AbgFIJP3 (ORCPT ); Tue, 9 Jun 2020 05:15:29 -0400 IronPort-SDR: wDxBlxE1goElNLjzWI1owja+MkbhW0cN60lmx0+C7yBJqmUt459E+XyY0H59np+nTtSk9kVX5M idzBKddX6JSw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jun 2020 02:15:27 -0700 IronPort-SDR: zuVF1mpKEINGAUTfFgnW32ujP1+dFBFdKRMr5TZil/7TzHAJ8widMg9onu+E1zBPM7s1hY41vc yQpBURsN6aiA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,491,1583222400"; d="scan'208";a="259739056" Received: from gklab-125-110.igk.intel.com ([10.91.125.110]) by orsmga007.jf.intel.com with ESMTP; 09 Jun 2020 02:15:25 -0700 From: Piotr Stankiewicz To: Bjorn Helgaas , linux-pci@vger.kernel.org Cc: Andy Shevchenko , Piotr Stankiewicz , "Rafael J. Wysocki" , Randy Dunlap , Jian-Hong Pan , Arnd Bergmann , Greg Kroah-Hartman , Logan Gunthorpe , linux-kernel@vger.kernel.org Subject: [PATCH v3 01/15] PCI/MSI: Forward MSI-X vector enable error code in pci_alloc_irq_vectors_affinity() Date: Tue, 9 Jun 2020 11:14:39 +0200 Message-Id: <20200609091440.497-1-piotr.stankiewicz@intel.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200609091148.32749-1-piotr.stankiewicz@intel.com> References: <20200609091148.32749-1-piotr.stankiewicz@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When debugging an issue where I was asking the PCI machinery to enable a set of MSI-X vectors, without falling back on MSI, I ran across a behaviour which seems odd. The pci_alloc_irq_vectors_affinity() will always return -ENOSPC on failure, when allocating MSI-X vectors only, whereas with MSI fallback it will forward any error returned by __pci_enable_msi_range(). This is a confusing behaviour, so have the pci_alloc_irq_vectors_affinity() forward the error code from __pci_enable_msix_range() when appropriate. Signed-off-by: Piotr Stankiewicz Reviewed-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig --- drivers/pci/msi.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 6b43a5455c7a..cade9be68b09 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1191,8 +1191,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, struct irq_affinity *affd) { struct irq_affinity msi_default_affd = {0}; - int msix_vecs = -ENOSPC; - int msi_vecs = -ENOSPC; + int nvecs = -ENOSPC; if (flags & PCI_IRQ_AFFINITY) { if (!affd) @@ -1203,17 +1202,16 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } if (flags & PCI_IRQ_MSIX) { - msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs, - max_vecs, affd, flags); - if (msix_vecs > 0) - return msix_vecs; + nvecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs, + affd, flags); + if (nvecs > 0) + return nvecs; } if (flags & PCI_IRQ_MSI) { - msi_vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, - affd); - if (msi_vecs > 0) - return msi_vecs; + nvecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd); + if (nvecs > 0) + return nvecs; } /* use legacy IRQ if allowed */ @@ -1231,9 +1229,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } } - if (msix_vecs == -ENOSPC) - return -ENOSPC; - return msi_vecs; + return nvecs; } EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);