On Thu, Jan 21, 2016 at 11:58:26PM +0100, Rafael J. Wysocki wrote: > On Thu, Jan 21, 2016 at 3:41 PM, Cao jin <caoj.fnst@xxxxxxxxxxxxxx> wrote: > > Hi, > > > > IMHO, I think maybe modification on i801_smbus driver is easier. > > > > Because when i801_smbus request_irq using pci_dev->irq, this > > pci_dev->irq seems still holds the value read from register( > > pci_setup_device->pci_read_irq), if the value is 255, it is invalid in > > register, > > Right. > > Which is why the PCI core should not leak it into the driver's ->probe callback. Is there a reserved IRQ value we could use to mean "invalid"? I guess we have NR_IRQS as a ceiling, so the range of valid IRQs would be [0 .. NR_IRQS - 1]. It looks like irq_desc() and a few drivers already rely on NR_IRQS being the bound: lpc32xx_kscan_probe lpc32xx_nand_probe pcmcia_setup_isa_irq lpc32xx_rtc_probe apbuart_verify_port ar933x_uart_verify_port lqasc_verify_port So I guess we could use ~0 as "invalid IRQ", and maybe the PCI core could set dev->irq to ~0 in these cases, and drivers like i801_smbus could check for that. Maybe a wrapper like irq_valid() would be useful. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
