| commit | eebb3e8d8aaf28f4bcaf12fd3645350bfd2f0b36 | [log] [tgz] |
|---|---|---|
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | Sat Dec 12 02:45:06 2015 +0100 |
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | Thu Jan 07 14:11:32 2016 +0100 |
| tree | 5d74ba65967afd6e6c1931887827a5abe66afc5d | |
| parent | c3a49cf35ead83829e54fc771a3acc1b1aa6dfd8 [diff] |
ACPI / LPSS: override power state for LPSS DMA device This is a third approach to workaround long standing issue with LPSS on BayTrail. First one [1] was reverted since it didn't resolve the issue comprehensively. Second one [2] was rejected by internal review. The LPSS DMA controller does not have neither _PS0 nor _PS3 method. Moreover it can be powered off automatically whenever the last LPSS device goes down. In case of no power any access to the DMA controller will hang the system. The behaviour is reproduced on some HP laptops based on Intel BayTrail [3,4] as well as on ASuS T100TA transformer. Power on the LPSS island through the registers accessible in a specific way. [1] http://www.spinics.net/lists/linux-acpi/msg53963.html [2] https://bugzilla.redhat.com/attachment.cgi?id=1066779&action=diff [3] https://bugzilla.redhat.com/show_bug.cgi?id=1184273 [4] http://www.spinics.net/lists/dmaengine/msg01514.html Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>