On 03/10/2017 10:35 AM, Romain Perier wrote: > Currently, the audio sampler clock is enabled from dw_hdmi_setup() at > step E. and is kept enabled for later use. This clock should be enabled > and disabled along with the actual audio stream and not always on (that > is bad for PM). Futhermore, this might cause sound glitches with some > HDMI devices, as the CTS+N is forced to zero when the stream is disabled > while the audio clock is still running. > > This commit adds a parameter to hdmi_audio_enable_clk() that controls > when the audio sample clock must be enabled or disabled. Then, it moves > the call to this function into dw_hdmi_audio_enable() and > dw_hdmi_audio_disable(). > > Signed-off-by: Romain Perier <romain.perier@xxxxxxxxxxxxx> > --- > drivers/gpu/drm/bridge/dw-hdmi.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > Hi Romain, Russell, Jose, This is a little out of scope, but I was wondering why the CTS calculation was not left in AUTO mode in the dw-hdmi driver ? In the Amlogic Vendor tree, they don't set the HDMI_AUD_CTS3_CTS_MANUAL bit and leave the CTS value to 0. I am wondering if the AUTO feature is specific to newer IP version, or it was disabled in the iMX.6 IP configuration ? or simply tied to the AHB audio specificity. It would be simpler and smarter to leave the AUTO feature enabled for I2S and S/PDIF input when the IP supports it. Jose, is there a config bit for this feature, or a specific IP version where it landed ? Anyway, we should really differentiate the AHB audio and I2S/SPDIF audio in the CTS/N calculation, since the I2S/SPDIF depends on an different clock for audio input and the AUTO CTS calculation feature will certainly offer a better clock synchronization. Thanks, Neil _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
