From: Lubomir Rintel lkundrak@v3.sk
[ Upstream commit 4a73a36cb704813f588af13d9842d0ba5a185758 ]
This lets NetworkManager/ModemManager know that this is a modem and needs to be connected first.
Signed-off-by: Lubomir Rintel lkundrak@v3.sk Link: https://patch.msgid.link/20250814154214.250103-1-lkundrak@v3.sk Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org ---
LLM Generated explanations, may be completely bogus:
**Backport Status: YES**
This commit should be backported to stable kernel trees for the following reasons:
## Analysis of the Commit:
1. **Nature of the change**: This is a simple device ID addition that adds USB vendor/device ID pair (0x8087:0x095a) for the Intel OEM version of Fibocom L850-GL modem to the cdc_ncm driver's device table.
2. **Bug fix vs feature**: This is a **hardware enablement fix** rather than a new feature. Without this change, the Intel-branded Fibocom L850-GL modem won't be properly recognized as a WWAN device, causing NetworkManager/ModemManager to fail to handle it correctly. This directly impacts users with this hardware.
3. **Code impact**: The change is minimal - just 7 lines adding a new entry to the `cdc_devs[]` USB device table: ```c /* Intel modem (label from OEM reads Fibocom L850-GL) */ { USB_DEVICE_AND_INTERFACE_INFO(0x8087, 0x095a, USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE), .driver_info = (unsigned long)&wwan_info, }, ```
4. **Risk assessment**: - **Extremely low risk** - The change only adds a new device ID entry - No existing functionality is modified - Uses the existing `wwan_info` driver configuration (FLAG_WWAN flag) - Follows the same pattern as other WWAN devices in the driver - Cannot cause regressions for other hardware
5. **User impact**: Users with this specific hardware (Intel OEM version with VID:PID 0x8087:0x095a) cannot use their modem properly without this fix. The modem won't be recognized as a WWAN device, preventing proper network management.
6. **Stable tree criteria compliance**: - ✓ Fixes a real bug (hardware not working properly) - ✓ Minimal change (7 lines) - ✓ No architectural changes - ✓ Self-contained to specific hardware - ✓ Clear and obvious correctness
7. **Historical context**: The git history shows numerous quirks and fixes for the Fibocom L850-GL modem variants, indicating this is well-known hardware that has required various fixes over time. This particular Intel OEM variant (0x8087:0x095a) was simply missing from the device table.
This is a textbook example of a stable-worthy commit: it enables specific hardware that should already be working, with zero risk to existing functionality.
drivers/net/usb/cdc_ncm.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index ea0e5e276cd6..5d123df0a866 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -2087,6 +2087,13 @@ static const struct usb_device_id cdc_devs[] = { .driver_info = (unsigned long)&wwan_info, },
+ /* Intel modem (label from OEM reads Fibocom L850-GL) */ + { USB_DEVICE_AND_INTERFACE_INFO(0x8087, 0x095a, + USB_CLASS_COMM, + USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE), + .driver_info = (unsigned long)&wwan_info, + }, + /* DisplayLink docking stations */ { .match_flags = USB_DEVICE_ID_MATCH_INT_INFO | USB_DEVICE_ID_MATCH_VENDOR,