在 2018/7/16 22:16, Lukas Wunner 写道:
On Mon, Jul 16, 2018 at 03:52:45PM +0800, Hui Wang wrote:
On 2018???07???16??? 14:06, Jim Qu wrote:
On modern laptop, there are more and more platforms have two GPUs, and each of them maybe have audio codec for HDMP/DP output. For some dGPU which is no output, audio codec usually is disabled.
In currect HDA audio driver, it will set all codec as VGA_SWITCHEROO_DIS, the audio which is binded to UMA will be suspended if user use debugfs to control power
In HDA driver side, it is difficult to know which GPU the audio has bound to. So set the bound gpu pci dev to vgaswitchreoo, the correct audio id will be set in vgaswitchreoo enable function.
Signed-off-by: Jim Qu Jim.Qu@amd.com
Is it possible to send this patch to stable@vger.kernel.org as well, then we will know that it is safe to backport this patch to the linux kernels with different version.
For which hardware do you want it in stable kernels?
This patch pertains to manual power control, which is only used on the MacBook Pro by default. And there are no MacBook Pros with AMD APUs. On all other hardware, users have to specify "amdgpu.runpm=0" on the command line to see any benefit from this patch. Also, manual power control will likely be removed once we get runtime PM working with muxed systems (such as the MacBook Pro).
The patch idea will deal with the issues 1) manual power control after v4.17. 2) driver control before v4.17. As we know current a lot of mainstream OS, such like ubuntu 16.04.4 (kernel is v4.15), ubuntu 18.04(kernel is v4.15), RHEL7.x (kernel is 3.1x). BTW, I believe you will see more and more products with AMD next generation of APUs in the near future.
Thanks JimQu
Lukas