diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index 06663d3..b6edb18 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -35,6 +35,11 @@ int pci_enable_rom(struct pci_dev *pdev)
 	if (res->flags & IORESOURCE_ROM_SHADOW)
 		return 0;
 
+	/*
+	 * Ideally pci_update_resource() would update the ROM BAR address,
+	 * and we would only set the enable bit here.  But apparently some
+	 * devices have buggy ROM BARs that read as zero when disabled.
+	 */
 	pcibios_resource_to_bus(pdev->bus, &region, res);
 	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
 	rom_addr &= ~PCI_ROM_ADDRESS_MASK;