Suspend to RAM freeze with kernel modesetting

[wferi <wferi@niif.hu>]

Hi ACPI folks,

I'd like to solicit your opinion on the
https://bugs.freedesktop.org/show_bug.cgi?id=22126 issue.
In short, if I load the Intel graphics driver with kernel
modesetting enabled, my ThinkPad R50e won't suspend to RAM
anymore, it freezes instead (ie. does not enter S3).
Tracing seems to show that the freeze happens in a
particular line of drivers/acpi/acpica/hwsleep.c:

/* Run the _PTS method */
status = acpi_evaluate_object(NULL, METHOD_NAME__PTS, &arg_list, NULL);

in acpi_enter_sleep_state_prep, as described in the bug
report. Can anybody provide a clue why this happens?
Suspend to disk works invariably, just like suspend to RAM
until I enable the kernel modesetting by a module option.

Please Cc me or the bug report, I'm not subscribed to linux-acpi.

Thanks,
Feri.