diff options
| author | Christoph Hellwig <hch@lst.de> | 2016-10-18 09:00:52 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2016-10-19 19:18:16 +0200 |
| commit | 17a51f12cfbd2814fd35966a069b242569c53e27 (patch) | |
| tree | ac00dfa3303d195b0dd8929d3f6c9c585b021351 | |
| parent | Linux 4.9-rc1 (diff) | |
| download | linux-17a51f12cfbd2814fd35966a069b242569c53e27.tar.xz linux-17a51f12cfbd2814fd35966a069b242569c53e27.zip | |
ahci: only try to use multi-MSI mode if there is more than 1 port
We should only try to allocate multiple MSI or MSI-X vectors if the device
actually has multiple ports. Otherwise pci_alloc_irq_vectors will return
a single vector due to n_ports = 1, in which case we shouldn't set the
AHCI_HFLAG_MULTI_MSI flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: 0b9e2988 ("ahci: use pci_alloc_irq_vectors")
Reported-by: Emmanuel Benisty <benisty.e@gmail.com>
Tested-by: Emmanuel Benisty <benisty.e@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | drivers/ata/ahci.c | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index ba5f11cebee2..ed311a040fed 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1418,21 +1418,24 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports, * Message mode could be enforced. In this case assume that advantage * of multipe MSIs is negated and use single MSI mode instead. */ - nvec = pci_alloc_irq_vectors(pdev, n_ports, INT_MAX, - PCI_IRQ_MSIX | PCI_IRQ_MSI); - if (nvec > 0) { - if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) { - hpriv->get_irq_vector = ahci_get_irq_vector; - hpriv->flags |= AHCI_HFLAG_MULTI_MSI; - return nvec; - } + if (n_ports > 1) { + nvec = pci_alloc_irq_vectors(pdev, n_ports, INT_MAX, + PCI_IRQ_MSIX | PCI_IRQ_MSI); + if (nvec > 0) { + if (!(readl(hpriv->mmio + HOST_CTL) & HOST_MRSM)) { + hpriv->get_irq_vector = ahci_get_irq_vector; + hpriv->flags |= AHCI_HFLAG_MULTI_MSI; + return nvec; + } - /* - * Fallback to single MSI mode if the controller enforced MRSM - * mode. - */ - printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n"); - pci_free_irq_vectors(pdev); + /* + * Fallback to single MSI mode if the controller + * enforced MRSM mode. + */ + printk(KERN_INFO + "ahci: MRSM is on, fallback to single MSI\n"); + pci_free_irq_vectors(pdev); + } } /* |