Re: Sierra Wireless EM9191 integration issues in mhi+wwan

[Manivannan Sadhasivam <mani@kernel.org>]

On Tue, Nov 02, 2021 at 05:13:58PM +0100, Aleksander Morgado wrote:
> Hey Mani,
> 
> > > [    7.189547] mhi mhi0: Transitioning from PM state: Linkdown or
> > > Error Fatal Detect to: SYS ERROR Process
> >
> > Hmm, I think the use of sync_power_up might be causing the issue here as it
> > forces the MHI state to fatal error.
> >
> > Ignore the previous diff and try the below one:
> >
> > diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
> > index 59a4896a8030..b1e8c7de4e54 100644
> > --- a/drivers/bus/mhi/pci_generic.c
> > +++ b/drivers/bus/mhi/pci_generic.c
> > @@ -637,7 +637,7 @@ static void mhi_pci_recovery_work(struct work_struct *work)
> >         if (err)
> >                 goto err_try_reset;
> >
> > -       err = mhi_sync_power_up(mhi_cntrl);
> > +       err = mhi_async_power_up(mhi_cntrl);

Doh! Sorry, I modified the wrong function. Here is the correct one:

diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
index 59a4896a8030..1e3c74bfbe34 100644
--- a/drivers/bus/mhi/pci_generic.c
+++ b/drivers/bus/mhi/pci_generic.c
@@ -743,7 +743,7 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
                goto err_unregister;
        }
 
-       err = mhi_sync_power_up(mhi_cntrl);
+       err = mhi_async_power_up(mhi_cntrl);
        if (err) {
                dev_err(&pdev->dev, "failed to power up MHI controller\n");
                goto err_unprepare;

Let's see how it goes :)

Thanks,
Mani