Hello Mark,
On Mon, Mar 17, 2025 at 04:45:31PM +0000, Mark Brown wrote:
> On Mon, Mar 17, 2025 at 08:44:01AM -0700, Breno Leitao wrote:
> > My UEFI machines with tegra210-quad consistently report "device reset
> > failed". Investigation showed this isn't an actual failure
> > - __device_reset() returns -ENOENT because ACPI has no "*_RST" method.
>
> That's not the case, it's returning an error because there is no reset
> controller discoverable via any mechanism.
>
Sorry, I was not very familiar with this subsystem, but I chase down
__device_reset(), and I found the return was coming from:
int __device_reset(struct device *dev, bool optional)
{
acpi_handle handle = ACPI_HANDLE(dev);
if (handle) {
if (!acpi_has_method(handle, "_RST"))
return optional ? 0 : -ENOENT;
> There's no specific handling for ACPI here.
Do you mean no _RST method as stated above?
> It's also not clear that this is a false positive, the
> driver did indeed fail to reset the device and especially for the error
> handling case that seems like relevant information.
If the driver failed to reset the device, then device_reset_optional()
it will return an error code, but it will not return an error code if
the RST method is not found, right?
Sorry, if I am mis-understading the code here.
> At the very least the changelog should be clarified.
What would you add to the changelog to make this clear?
Thanks for the quick review!
--breno
