[PATCH 1/2] ata: pata_artop: read the ATP865 mode register through pci_iomap
From: Daniel Palmer
Date: Sat Oct 17 2026 - 00:14:46 EST
artop_init_one() probes the 6280's "fast" bit with inb() on the raw
start address of BAR 4. That address is a PCI I/O address, which is
only a usable port number on platforms whose I/O port base maps PCI I/O
space one to one. On an SH7751 LANDISK (identity io_port_base, PCI I/O
window at 0xfe240000) the resource starts at 0x1400 and inb(0x1400)
dereferences that address:
BUG: unable to handle kernel paging request at 00001400
PC is at artop_init_one+0x10e/0x170
Map the BAR with pci_iomap() and use ioread8(), as libata-sff does for
the BMDMA registers later on.
Signed-off-by: Daniel Palmer <daniel@xxxxxxxx>
---
drivers/ata/pata_artop.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/ata/pata_artop.c b/drivers/ata/pata_artop.c
index 9f8d41639a62..351ff4c8e48e 100644
--- a/drivers/ata/pata_artop.c
+++ b/drivers/ata/pata_artop.c
@@ -405,13 +405,21 @@ static int artop_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
case 1: /* 6260 */
ppi[0] = &info_626x;
break;
- case 2: /* 6280 or 6280 + fast */
- if (inb(pci_resource_start(pdev, 4)) & 0x10)
+ case 2: { /* 6280 or 6280 + fast */
+ void __iomem *bmdma = pci_iomap(pdev, 4, 1);
+ u8 cfg;
+
+ if (!bmdma)
+ return -ENOMEM;
+ cfg = ioread8(bmdma);
+ pci_iounmap(pdev, bmdma);
+ if (cfg & 0x10)
ppi[0] = &info_628x_fast;
else
ppi[0] = &info_628x;
break;
}
+ }
BUG_ON(ppi[0] == NULL);
--
2.55.0