On Sun, Jul 16, 2017 at 12:43:10AM +0300, Sergei Shtylyov wrote:
> of_irq_get() may return a negative error number as well as 0 on failure,
> while the driver only checks for 0, blithely continuing with the call to
> irq_set_chained_handler_and_data() -- that function expects *unsigned int*
> so should probably do nothing when a large IRQ number resulting from a
> conversion of a negative error number is passed to it. The driver then
> probes successfully while being only partly functional...
>
> Check for 'irq <= 0' instead and propagate the negative error number to
> the probe method -- that will allow the deferred probing as well...
>
> Fixes: d3c68e0a7e34 ("PCI: faraday: Add Faraday Technology FTPCI100 PCI Host Bridge driver")
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Applied with Linus' reviewed-by to pci/host-faraday for v4.14, thanks!
> ---
> drivers/pci/host/pci-ftpci100.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> Index: pci/drivers/pci/host/pci-ftpci100.c
> ===================================================================
> --- pci.orig/drivers/pci/host/pci-ftpci100.c
> +++ pci/drivers/pci/host/pci-ftpci100.c
> @@ -350,9 +350,9 @@ static int faraday_pci_setup_cascaded_ir
>
> /* All PCI IRQs cascade off this one */
> irq = of_irq_get(intc, 0);
> - if (!irq) {
> + if (irq <= 0) {
> dev_err(p->dev, "failed to get parent IRQ\n");
> - return -EINVAL;
> + return irq ?: -EINVAL;
> }
>
> p->irqdomain = irq_domain_add_linear(intc, 4,
>
