On Thu, Nov 23, 2017 at 09:27:19AM +0800, Ching Huang wrote: > From: Ching Huang <ching2048@xxxxxxxxxxxx> > > Add module parameter msi_enable to has a chance to disable msi interrupt if it does not work properly. > > Signed-off-by: Ching Huang <ching2048@xxxxxxxxxxxx> > --- > > diff -uprN a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c > --- a/drivers/scsi/arcmsr/arcmsr_hba.c 2017-11-23 14:29:26.000000000 +0800 > +++ b/drivers/scsi/arcmsr/arcmsr_hba.c 2017-11-23 16:02:28.000000000 +0800 > @@ -75,6 +75,10 @@ MODULE_DESCRIPTION("Areca ARC11xx/12xx/1 > MODULE_LICENSE("Dual BSD/GPL"); > MODULE_VERSION(ARCMSR_DRIVER_VERSION); > > +static int msi_enable = 1; > +module_param(msi_enable, int, S_IRUGO); ^^^^^^^ checkpatch.pl will complain that this should be 0444 > +MODULE_PARM_DESC(msi_enable, " Enable MSI interrupt(0 ~ 1), msi_enable=1(enable), =0(disable)"); ^ Remove the extra space > + > static int host_can_queue = ARCMSR_DEFAULT_OUTSTANDING_CMD; > module_param(host_can_queue, int, S_IRUGO); > MODULE_PARM_DESC(host_can_queue, " adapter queue depth(32 ~ 1024), default is 128"); > @@ -831,11 +835,15 @@ arcmsr_request_irq(struct pci_dev *pdev, > pr_info("arcmsr%d: msi-x enabled\n", acb->host->host_no); > flags = 0; > } else { > - nvec = pci_alloc_irq_vectors(pdev, 1, 1, > - PCI_IRQ_MSI | PCI_IRQ_LEGACY); > + if (msi_enable == 1) > + nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI); > + else > + nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_LEGACY); > if (nvec < 1) > return FAILED; I feel like we should try PCI_IRQ_MSI then if it fails we could fall back to PCI_IRQ_LEGACY. Originally, it worked like this and now it just fails unless you toggle the module param. It's a regression. > > + if (msi_enable == 1) > + pr_info("arcmsr%d: msi enabled\n", acb->host->host_no); This printk could be improved. Use dev_info(&pdev->dev, for a start. I know that the other prints don't use this, but we could use it one time then slowly add more users until more are using dev_info() than pr_info() and then someone will decide to clean up the old users. regards, dan carpenter