Some PA-RISC servers have BMC management cards (Diva) with up to 5 serial
UARTS per memory PCI bar. This triggers since at least kernel 6.12 for each of
the UARTS (beside the first one) the following warning in devres.c:
0000:00:02.0: ttyS2 at MMIO 0xf0822000 (irq = 21, base_baud = 115200) is a 16550A
0000:00:02.0: ttyS3 at MMIO 0xf0822010 (irq = 21, base_baud = 115200) is a 16550A
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1 at drivers/pci/devres.c:603 pcim_add_mapping_to_legacy_table+0x5c/0x8c
CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.11+ #2621
Hardware name: 9000/778/B160L
IAOQ[0]: pcim_add_mapping_to_legacy_table+0x5c/0x8c
IAOQ[1]: pcim_add_mapping_to_legacy_table+0x60/0x8c
RP(r2): pcim_add_mapping_to_legacy_table+0x4c/0x8c
Backtrace:
[<10c1eb10>] pcim_iomap+0xd4/0x10c
[<10ca8784>] serial8250_pci_setup_port+0xa8/0x11c
[<10ca9a34>] pci_hp_diva_setup+0x6c/0xc4
[<10cab134>] pciserial_init_ports+0x150/0x324
[<10cab470>] pciserial_init_one+0xfc/0x20c
[<10c14780>] pci_device_probe+0xc0/0x190
...
---[ end trace 0000000000000000 ]---
I see three options to avoid this warning:
a) drop the WARNING() from devrec.c,
b) modify pcim_iomap() to return an existing mapping if it exists
instead of creating a new mapping, or
c) change serial8250_pci_setup_port() to only create a new mapping
if none exists yet.
This patch implements option c).
Signed-off-by: Helge Deller <deller@xxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v6.12+
diff --git a/drivers/tty/serial/8250/8250_pcilib.c b/drivers/tty/serial/8250/8250_pcilib.c
index ea906d721b2c..fc024bf86c1f 100644
--- a/drivers/tty/serial/8250/8250_pcilib.c
+++ b/drivers/tty/serial/8250/8250_pcilib.c
@@ -19,7 +19,9 @@ int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
return -EINVAL;
if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
- if (!pcim_iomap(dev, bar, 0) && !pcim_iomap_table(dev))
+ /* might have been mapped already with other offset */
+ if (!pcim_iomap_table(dev) || !pcim_iomap_table(dev)[bar] ||
+ !pcim_iomap(dev, bar, 0))
return -ENOMEM;
port->port.iotype = UPIO_MEM;
