Re: [PATCH RFC v2] bus: mhi: host: pci_generic: Add MBIM-mode config for generic SDX65

[Jeff Hugo <jeff.hugo@oss.qualcomm.com>]

On 11/10/2026 6:06 PM, Haipeng Lin via B4 Relay wrote:
> From: Haipeng Lin <jimmie.lin@gmail.com>
> 
> The Surface Pro 11 5G carries an SDX65 that enumerates with Qualcomm's
> generic IDs (17cb:0308, subsystem 17cb:0308) but runs the MBIM-mode
> firmware it ships with for Windows.
> 
> Control is MBIM only (the QMI channel never answers), and data on
> channels 100/101 is framed as MBIM NTBs: the modem reports a WDA data
> format of raw IP with MBIM aggregation, up to 32 KiB downlink.
> 
> The generic qcom-sdx65m entry names channels 100/101 "IP_HW0", which
> binds mhi_net. mhi_net expects raw IP, so no data session can work.
> The MBIM-mode modules in this driver name them "IP_HW0_MBIM" instead
> which binds mhi_wwan_mbim.
> 
> Boards with a Qualcomm-ID modem in MBIM mode have so far been told
> apart by subsystem ID, like the SC8280XP CRD's SDX55 (17cb:010c).
> This modem carries the generic subsystem ID, so select an MBIM
> configuration by machine compatible instead.
I'd like it if we could query the hardware to determine if it is in this 
mode as maybe one of these systems has a SDX65 dongle attached where 
this workaround does not apply.  However, I am failing to identify such 
a mechanism so what you have proposed seem to be the best solution so far.

Unless someone identifies a better idea, this seems reasonable given the 
situation.

-Jeff