[PATCH] serial: 8250_pci: add support for the AX99100
From: Martin Roukala (né Peres)
Date: Mon Mar 09 2026 - 09:56:02 EST
This is found in popular brands such as StarTech.com or Delock, and has
been a source of frustration to quite a few people, if I can trust
Amazon comments complaining about Linux support via the official
out-of-the-tree driver.
Signed-off-by: Martin Roukala (né Peres) <martin.roukala@xxxxxxxxx>
---
I have been carrying this patch for 5+ years, without experiencing any
problem related to it... so I thought it would be a good time to start
upstreaming it and solving the lack of support for the AX99100 for more
than just me and users of my packages.
---
drivers/tty/serial/8250/8250_pci.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index aa1ab4da9ff1..6cfd1b2af5b7 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -137,6 +137,8 @@ struct serial_private {
};
#define PCI_DEVICE_ID_HPE_PCI_SERIAL 0x37e
+#define PCIE_VENDOR_ID_ASIX 0x125B
+#define PCIE_DEVICE_ID_AX99100 0x9100
static const struct pci_device_id pci_use_msi[] = {
{ PCI_DEVICE_SUB(PCI_VENDOR_ID_NETMOS, PCI_DEVICE_ID_NETMOS_9900,
@@ -149,6 +151,8 @@ static const struct pci_device_id pci_use_msi[] = {
0xA000, 0x1000) },
{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP_3PAR, PCI_DEVICE_ID_HPE_PCI_SERIAL,
PCI_ANY_ID, PCI_ANY_ID) },
+ { PCI_DEVICE_SUB(PCIE_VENDOR_ID_ASIX, PCIE_DEVICE_ID_AX99100,
+ 0xA000, 0x1000) },
{ }
};
@@ -920,6 +924,7 @@ static int pci_netmos_init(struct pci_dev *dev)
case PCI_DEVICE_ID_NETMOS_9912:
case PCI_DEVICE_ID_NETMOS_9922:
case PCI_DEVICE_ID_NETMOS_9900:
+ case PCIE_DEVICE_ID_AX99100:
num_serial = pci_netmos_9900_numports(dev);
break;
@@ -2544,6 +2549,14 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
.init = pci_netmos_init,
.setup = pci_netmos_9900_setup,
},
+ {
+ .vendor = PCIE_VENDOR_ID_ASIX,
+ .device = PCI_ANY_ID,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .init = pci_netmos_init,
+ .setup = pci_netmos_9900_setup,
+ },
/*
* EndRun Technologies
*/
@@ -6065,6 +6078,10 @@ static const struct pci_device_id serial_pci_tbl[] = {
0xA000, 0x3002,
0, 0, pbn_NETMOS9900_2s_115200 },
+ { PCIE_VENDOR_ID_ASIX, PCIE_DEVICE_ID_AX99100,
+ 0xA000, 0x1000,
+ 0, 0, pbn_b0_1_115200 },
+
/*
* Best Connectivity and Rosewill PCI Multi I/O cards
*/
---
base-commit: 1f318b96cc84d7c2ab792fcc0bfd42a7ca890681
change-id: 20260309-8250_pci_ax99100-d4ee75bbdab3
Best regards,
--
Martin Roukala (né Peres) <martin.roukala@xxxxxxxxx>