On Wed, Apr 29, 2020 at 5:38 PM Daniil Lunev <dlu...@chromium.org> wrote:
>
> [to make it appear on the mailing list as I didn't realize I was in
> hypertext sending mode]
>
> On Thu, Apr 30, 2020 at 10:11 AM Daniil Lunev <dlu...@chromium.org> wrote:
> >
> > Hi Enric.
> > I encountered the issue on a Hatch device when trying running 5.4 kernel on
> > that. After talking to Prashant it seems that any device with coreboot
> > built before a certain point (a particular fix for device hierarchy in ACPI
> > tables of Chrome devices which happened in mid-April) will not be able to
> > correctly initialize the driver and will get a kernel panic trying to do so.
A clarifying detail here: This should not be seen in any current
*production* device. No prod device firmware will carry the erroneous
ACPI device entry.
> > Thanks,
> > Daniil
> >
> > On Thu, Apr 30, 2020 at 7:58 AM Enric Balletbo i Serra
> > <enric.balle...@collabora.com> wrote:
> >>
> >> Hi Daniil,
> >>
> >> Thank you for the patch.
> >>
> >> On 28/4/20 3:02, Daniil Lunev wrote:
> >> > Missing EC in device hierarchy causes NULL pointer to be returned to the
> >> > probe function which leads to NULL pointer dereference when trying to
> >> > send a command to the EC. This can be the case if the device is missing
> >> > or incorrectly configured in the firmware blob. Even if the situation
> >>
> >> There is any production device with a buggy firmware outside? Or this is
> >> just
> >> for defensive programming while developing the firmware? Which device is
> >> affected for this issue?
> >>
> >> Thanks,
> >> Enric
> >>
> >> > occures, the driver shall not cause a kernel panic as the condition is
> >> > not critical for the system functions.
> >> >
> >> > Signed-off-by: Daniil Lunev <dlu...@chromium.org>
> >> > ---
> >> >
> >> > drivers/platform/chrome/cros_ec_typec.c | 5 +++++
> >> > 1 file changed, 5 insertions(+)
> >> >
> >> > diff --git a/drivers/platform/chrome/cros_ec_typec.c
> >> > b/drivers/platform/chrome/cros_ec_typec.c
> >> > index 874269c07073..30d99c930445 100644
> >> > --- a/drivers/platform/chrome/cros_ec_typec.c
> >> > +++ b/drivers/platform/chrome/cros_ec_typec.c
> >> > @@ -301,6 +301,11 @@ static int cros_typec_probe(struct platform_device
> >> > *pdev)
> >> >
> >> > typec->dev = dev;
> >> > typec->ec = dev_get_drvdata(pdev->dev.parent);
> >> > + if (!typec->ec) {
> >> > + dev_err(dev, "Failed to get Cros EC data\n");
> >> > + return -EINVAL;
> >> > + }
> >> > +
> >> > platform_set_drvdata(pdev, typec);
> >> >
> >> > ret = cros_typec_get_cmd_version(typec);
> >> >
