Concern about commit bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR_ID for VF's to check status
"Slark Xiao" <[email protected]> Wed, 27 May 2026 16:28:57 +0800 (CST)
| Newsgroups | dev.linux.lists.mhi,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
Hi Mani, I got a problem recently about the health_check function. It's disabled in my Thinkpad X1 Gen14. After checking, this feature was disbaled because the commit bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR_ID for VF's to check status. This commit only allows the device that the value "pdev->is_physfn" is true to enable health check. But I don't know why my PC and WWAN device would get a false result. Test result as below: [ 3.920101] mhi-pci-generic 0000:08:00.0: MHI PCI device found: foxconn-t99w696 [ 3.920113] mhi-pci-generic 0000:08:00.0: ##debug## mhi_cntrl_config is assign [ 3.920114] mhi-pci-generic 0000:08:00.0: ##debug## mhi_pci_claim .. [ 3.920127] mhi-pci-generic 0000:08:00.0: enabling device (0000 -> 0002) [ 3.920179] mhi-pci-generic 0000:08:00.0: ##debug## mhi_pci_get_irqs .. [ 3.930223] mhi-pci-generic 0000:08:00.0: ##debug## mhi_register_controller .. [ 3.935268] mhi-pci-generic 0000:08:00.0: ##debug## mhi_prepare_for_power_up .. [ 3.935373] mhi-pci-generic 0000:08:00.0: ##debug## mhi_sync_power_up .. [ 3.935375] mhi mhi0: Requested to power ON [ 3.935388] mhi mhi0: Power on setup success [ 3.971342] mhi-pci-generic 0000:08:00.0: pdev->is_physfn is 0 [ 3.971346] mhi-pci-generic 0000:08:00.0: pdev->is_virtfn is 0 For my situation, both pdev->is_virtfn and pdev->is_physfn are false. And I also checked the requirement for pdev->is_physf, seems it will only be 1 if the device has SR-IOV capbility and the function is recognized as a PF. If your device is just a regular PCIe function or the kernel does not recognize the SR-IOV capability, it will be 0. So for mhi_pci_generic side, I suggest that we should modify it by using "!pdev->is_virtfn" instead of "pdev->is_physfn". Thanks