Hi, On 7/25/19 3:25 AM, Navid Emamdoost wrote: > pci_get_device may fail and return NULL. This eventually will be > dereferenced in __pci_register_driver. So null check is necessary. I'm sorry to say this but the patch is incorrect and should not be applied. ALI M1533 ISA bridge presence is optional (the driver can work also with other ISA bridges) and ali_isa_bridge is always correctly checked for NULL before being dereferenced in the driver. > Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx> > --- > drivers/ata/pata_ali.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/ata/pata_ali.c b/drivers/ata/pata_ali.c > index 0b122f903b8a..47d9bec1f2e2 100644 > --- a/drivers/ata/pata_ali.c > +++ b/drivers/ata/pata_ali.c > @@ -627,6 +627,8 @@ static int __init ali_init(void) > { > int ret; > ali_isa_bridge = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL); > + if (!ali_isa_bridge) > + return -EINVAL; > > ret = pci_register_driver(&ali_pci_driver); > if (ret < 0) Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics