From 2cf532f5e67c0cfe38c8c100e49280cdadacd2be Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Thu, 17 Apr 2014 18:06:15 +0200 Subject: ahci: Do not receive interrupts sent by dummy ports In multiple MSI mode all AHCI ports (including dummy) get assigned separate MSI vectors and (as result of execution pci_enable_msi_exact() function) separate IRQ numbers, (mapped to the MSI vectors). Therefore, although interrupts from dummy ports are not desired they are still enabled. We do not request IRQs for dummy ports, but that only means we do not assign AHCI-specific ISRs to corresponding IRQ numbers. As result, dummy port interrupts still could come and traverse all the way from the PCI device to the kernel, causing unnecessary overhead. This update disables IRQs for dummy ports and prevents the described issue. Signed-off-by: Alexander Gordeev Signed-off-by: Tejun Heo Tested-by: David Milburn Cc: linux-ide@vger.kernel.org Cc: stable@vger.kernel.org Fixes: 5ca72c4f7c41 ("AHCI: Support multiple MSIs") --- drivers/ata/ahci.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 44d40c746982..71e15b73513d 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1241,12 +1241,16 @@ int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis) for (i = 0; i < host->n_ports; i++) { struct ahci_port_priv *pp = host->ports[i]->private_data; - /* pp is NULL for dummy ports */ - if (pp) - rc = devm_request_threaded_irq(host->dev, - irq + i, ahci_hw_interrupt, - ahci_thread_fn, IRQF_SHARED, - pp->irq_desc, host->ports[i]); + /* Do not receive interrupts sent by dummy ports */ + if (!pp) { + disable_irq(irq + i); + continue; + } + + rc = devm_request_threaded_irq(host->dev, irq + i, + ahci_hw_interrupt, + ahci_thread_fn, IRQF_SHARED, + pp->irq_desc, host->ports[i]); if (rc) goto out_free_irqs; } -- cgit v1.2.3