[PATCH AUTOSEL 5.4 34/39] pcnet32: Use pci_resource_len to validate PCI resource

Sasha Levin
2021-04-12T16:38:03Z

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit 66c3f05ddc538ee796321210c906b6ae6fc0792a ]

pci_resource_start() is not a good indicator to determine if a PCI
resource exists or not, since the resource may start at address 0.
This is seen when trying to instantiate the driver in qemu for riscv32
or riscv64.

pci 0000:00:01.0: reg 0x10: [io 0x0000-0x001f]
pci 0000:00:01.0: reg 0x14: [mem 0x00000000-0x0000001f]
...
pcnet32: card has no PCI IO resources, aborting

Use pci_resouce_len() instead.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/amd/pcnet32.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/amd/pcnet32.c b/drivers/net/ethernet/amd/pcnet32.c
index f5ad12c10934..da84660ceae1 100644
--- a/drivers/net/ethernet/amd/pcnet32.c
+++ b/drivers/net/ethernet/amd/pcnet32.c
@@ -1548,8 +1548,7 @@ pcnet32_probe_pci(struct pci_dev *pdev, const struct pci_device_id *ent)
}
pci_set_master(pdev);

- ioaddr = pci_resource_start(pdev, 0);
- if (!ioaddr) {
+ if (!pci_resource_len(pdev, 0)) {
if (pcnet32_debug & NETIF_MSG_PROBE)
pr_err("card has no PCI IO resources, aborting\n");
err = -ENODEV;
@@ -1562,6 +1561,8 @@ pcnet32_probe_pci(struct pci_dev *pdev, const struct pci_device_id *ent)
pr_err("architecture does not support 32bit PCI busmaster DMA\n");
goto err_disable_dev;
}
+
+ ioaddr = pci_resource_start(pdev, 0);
if (!request_region(ioaddr, PCNET32_TOTAL_SIZE, "pcnet32_probe_pci")) {
if (pcnet32_debug & NETIF_MSG_PROBE)
pr_err("io address range already allocated\n");
--
2.30.2