Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Moritz Fischer <mdf@kernel.org>
To:     linux-pci@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, bhelgaas@google.com,
        moritzf@google.com, Moritz Fischer <mdf@kernel.org>,
        Brian Foley <bpfoley@google.com>
Subject: [PATCH] PCI/IOV: Clarify error message for unbound devices
Date:   Fri,  8 Jan 2021 14:06:30 -0800
Message-Id: <20210108220630.10863-1-mdf@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Be more verbose to disambiguate the error case when trying to configure
SRIOV with no driver bound vs. a driver that does not implement the
SRIOV callback.

Reported-by: Brian Foley <bpfoley@google.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
---
 drivers/pci/iov.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 4afd4ee4f7f0..f9ecc691daf5 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -304,8 +304,15 @@ static ssize_t sriov_numvfs_store(struct device *dev,
 	if (num_vfs == pdev->sriov->num_VFs)
 		goto exit;
 
+	/* is PF driver loaded */
+	if (!pdev->driver) {
+		pci_info(pdev, "No driver bound to device. Cannot configure SRIOV\n");
+		ret = -ENOENT;
+		goto exit;
+	}
+
 	/* is PF driver loaded w/callback */
-	if (!pdev->driver || !pdev->driver->sriov_configure) {
+	if (!pdev->driver->sriov_configure) {
 		pci_info(pdev, "Driver does not support SRIOV configuration via sysfs\n");
 		ret = -ENOENT;
 		goto exit;
-- 
2.29.2