Snapdragon X55 (Thinkpad X1 Nano w/5G Modem)

[Loic Poulain]

On Tue, 18 May 2021 at 13:21, Oskar Stenman <oskar at cetex.se> wrote:
>
> Hi!
>
> I couldn't figure out what to log in mhi_init_irq_setup but i put a logline on in mhi_init_dev_ctxt:
> oskar at oskar-ThinkPad-X1-Nano-Gen-1:~/src/linux-kernel/linux-upstream-5.12.0+/drivers/bus/mhi$ git diff .
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index c81b377fca8f..732affde7a20 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -266,6 +266,7 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
>         struct mhi_cmd *mhi_cmd;
>         u32 tmp;
>         int ret = -ENOMEM, i;
> +       struct device *dev = &mhi_cntrl->mhi_dev->dev;
>
>         atomic_set(&mhi_cntrl->dev_wake, 0);
>         atomic_set(&mhi_cntrl->pending_pkts, 0);
> @@ -333,6 +334,9 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
>
>                 er_ctxt->ertype = MHI_ER_TYPE_VALID;
>                 er_ctxt->msivec = mhi_event->irq;
> +               dev_warn(dev, "er_ctxt->msivec::%d\n",
> +                       er_ctxt->msivec);
> +
>                 mhi_event->db_cfg.db_mode = true;
>
>                 ring->el_size = sizeof(struct mhi_tre);
>
>
> With intel vt-d disabled:
> [   64.428320] mhi: loading out-of-tree module taints kernel.
> [   64.428455] mhi: module verification failed: signature and/or required key missing - tainting kernel
> [   98.714766] mhi-pci-generic 0000:08:00.0: BAR 0: assigned [mem 0xbc200000-0xbc200fff 64bit]
> [   98.714900] mhi-pci-generic 0000:08:00.0: enabling device (0000 -> 0002)
> [   98.715245] mhi-pci-generic 0000:08:00.0: using shared MSI
> [   98.715611] mhi mhi0: er_ctxt->msivec::0
> [   98.715614] mhi mhi0: er_ctxt->msivec::0
> [   98.715617] mhi mhi0: er_ctxt->msivec::0
> [   98.715623] mhi mhi0: er_ctxt->msivec::0
> [   98.715631] mhi mhi0: Requested to power ON
> [   98.716156] mhi mhi0: Power on setup success
> [   98.750461] mhi mhi0: Wait for device to enter SBL or Mission mode
>
> With intel vt-d enabled:
> [   64.750646] mhi: loading out-of-tree module taints kernel.
> [   64.750776] mhi: module verification failed: signature and/or required key missing - tainting kernel
> [   71.229020] mhi-pci-generic 0000:08:00.0: BAR 0: assigned [mem 0xbc200000-0xbc200fff 64bit]
> [   71.229153] mhi-pci-generic 0000:08:00.0: enabling device (0000 -> 0002)
> [   71.230017] mhi mhi0: er_ctxt->msivec::1
> [   71.230021] mhi mhi0: er_ctxt->msivec::2
> [   71.230024] mhi mhi0: er_ctxt->msivec::3
> [   71.230030] mhi mhi0: er_ctxt->msivec::4
> [   71.230038] mhi mhi0: Requested to power ON
> [   71.231107] mhi mhi0: Power on setup success
> [   71.264612] mhi mhi0: Wait for device to enter SBL or Mission mode
>
> Do i understand it correctly that this is correctly telling the modem to use shared irq and that this might be a modem firmware-bug?

Yes, at least MSI info seems correctly configured by the host in both
shared/non-shared cases.

Regards,
Loic