Hi Prashant, On 30/4/20 2:43, Prashant Malani wrote: > On Wed, Apr 29, 2020 at 5:38 PM Daniil Lunev <[email protected]> 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 <[email protected]> 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 for the clarification. Then, I don't think we need to upstream this. This kind of "defensive-programming" it's not something that should matter to upstream. Thanks, Enric >>> Thanks, >>> Daniil >>> >>> On Thu, Apr 30, 2020 at 7:58 AM Enric Balletbo i Serra >>> <[email protected]> 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 <[email protected]> >>>>> --- >>>>> >>>>> 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); >>>>>
