On 2018å¹´07æ??25æ?¥ 16:20, Takashi Iwai wrote: > On Wed, 25 Jul 2018 10:02:34 +0200, > jimqu wrote: >> >> >> On 2018å¹´07æ??25æ?¥ 13:46, Takashi Iwai wrote: >>> On Wed, 25 Jul 2018 07:38:37 +0200, >>> Qu, Jim wrote: >>>> Jim: Just like Alex said, we want driver can get eld info when hotplug in new device. amdgpu driver is a bit difference from radeon driver, it is not a suitable place to call notify() function in *_audio_enable() , since they are not in the hotplug process context like them in radeon driver, but the mode setting. >>>> >>>> IMO, the right place to call notify() function is also in the amdgpu_connector_xxxx_detect() in amdgpu_connector.c. >>> Hm, but by the modesetting, it actually enables / disables the audio >>> as well, no? If so, the notifier is exactly for that purpose. The >>> audio driver needs to know not only about the physical connection but >>> whether the audio can be actually driven. >>> >>> That is, even if the monitor is connected, the audio won't come out if >>> the mode is off. That is equivalent with the unplugged state for the >>> audio driver. >>> >>> The i915 driver deals with the notifier just like the above, so the >>> behavior is intentional. >>> >>> >>> thanks, >>> >>> Takashi >> I am afraid if device hotplug out, how is audio state if it follow up >> eld info? Since the modesetting is never performed for the display >> which is plugged out, so there is no notify() call on it. > In principle, the HDMI audio just needs to follows the video state, > and it doesn't need to care actual physical connections. As long as > video can go out, it's fine, audio can, too. When video is disabled > (even if connected), audio can't be used as well, so it must follow to > off, too. The notifier is used to follow this video state change. > > Practically seen, the user-space shall switch off the video > accordingly upon hot unplug, then the audio notifier is sent, and the > audio gets off, too. > > > thanks, > > Takashi Ok, that means there are other code pathes to update audio state. Anyway, for patch 3/4 Acked-by: Jim Qu <Jim.Qu at amd.com> There may be other concerns from Alex/Christian. Thanks JimQu
