On Mon, 20 Mar 2017 16:12:01 +0100, Ian W MORRISON wrote: > > On 20 March 2017 at 21:04, Takashi Iwai <tiwai@xxxxxxx> wrote: > > > On Mon, 20 Mar 2017 10:41:07 +0100, > > Ian W MORRISON wrote: > > > > > > On 20 March 2017 at 19:41, Takashi Iwai <tiwai@xxxxxxx> wrote: > > > > > > > On Mon, 20 Mar 2017 09:17:30 +0100, > > > > Ian W MORRISON wrote: > > > > > > > > > > Oops ... forgot to copy alsa-devel and Pierre-Louis. > > > > > > > > > > On 20 March 2017 at 18:59, Takashi Iwai <tiwai@xxxxxxx> wrote: > > > > > > > > > > > On Mon, 20 Mar 2017 08:42:32 +0100, > > > > > > Ian W MORRISON wrote: > > > > > > > > > > > > > > The upstream kernel builds for distributions such as Ubuntu > > which now > > > > > > > includes binary packages for v4.11 mainline kernel release > > > > candidates are > > > > > > > promoted as a way of testing upstream kernels to to confirm that > > > > upstream > > > > > > > has fixed a specific issue (see https://wiki.ubuntu.com/ > > > > > > > Kernel/MainlineBuilds). > > > > > > > > > > > > > > Unfortunately the long awaited patch for providing HDMI audio > > > > support for > > > > > > > Bay Trail and Cherry Trail devices does not include this support > > > > through > > > > > > a > > > > > > > module built by default. > > > > > > > > > > > > > > Through including by default of the two associated CONFIG > > settings > > > > > > (SND_X86 > > > > > > > and HDMI_LPE_AUDIO), upstream kernel builds would automatically > > > > provide > > > > > > the > > > > > > > much desired HDMI audio support by default. > > > > > > > > > > > > > > This patch uses a Kconfig 'default' statement to include the > > driver > > > > as > > > > > > > default. > > > > > > > > > > > > > > Changes in version 2: CONFIG_SND_X86 now a bool and changed > > default > > > > m to > > > > > > > default y > > > > > > > > > > > > > > Signed-off-by: Ian W Morrison <linuxium@xxxxxxxxxxxxxxx> > > > > > > > --- > > > > > > > sound/x86/Kconfig | 4 +++- > > > > > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > diff --git a/sound/x86/Kconfig b/sound/x86/Kconfig > > > > > > > index 84c8f8fc..cac2270 100644 > > > > > > > --- a/sound/x86/Kconfig > > > > > > > +++ b/sound/x86/Kconfig > > > > > > > @@ -1,6 +1,7 @@ > > > > > > > menuconfig SND_X86 > > > > > > > - tristate "X86 sound devices" > > > > > > > + bool "X86 sound devices" > > > > > > > depends on X86 > > > > > > > + default y > > > > > > > > > > > > This one is OK, but ... > > > > > > > > > > > > > ---help--- > > > > > > > X86 sound devices that don't fall under SoC or PCI > > > > categories > > > > > > > > > > > > > > @@ -9,6 +10,7 @@ if SND_X86 > > > > > > > config HDMI_LPE_AUDIO > > > > > > > tristate "HDMI audio without HDaudio on Intel Atom > > platforms" > > > > > > > depends on DRM_I915 > > > > > > > + default y > > > > > > > > > > > > ... this is wrong. Each driver config itself should be left > > > > > > unspecified. > > > > > > > > > > > > It's distributor's job to choose the right config here. > > > > > > > > > > > > Actually this goes back to one of my earlier points: A distributor > > > > doesn't > > > > > have to set 'HDMI' as HDMI audio is automatically provided. > > > > > > > > Provided by who...? > > > > > > > > > > > > > I suppose it is provided as a result of the architecture one runs the > > > primary Makefile on. With 'uname -m' returning 'x86_64' running 'make > > > defconfig' results in 'CONFIG_HDMI=y' being set so > > 'drivers/video/Makefile' > > > automatically makes 'drivers/video/hdmi.c' and as > > > 'arch/x86/configs/x86_64_defconfig' includes 'CONFIG_DRM=y' and > > > 'CONFIG_DRM_I915=y' and 'drivers/gpu/drm/i915/Makefile' makes > > > 'intel_audio.c'. > > > > The defconfig stuff supports only the limited device sets that are > > supposed to be very common. Is HDMI_LPE_AUDIO classified really as > > such a thing? I don't know... > > > > > In this instance I'd suggest that HDMI_LPE_AUDIO is common as without it > you do not get HDMI audio on all x86_64 devices. However see my comment > below. > > > > > > > > > This is just an > > > > > extension because by setting 'HDMI_LPE_AUDIO' the missing audio > > support > > > > for > > > > > BYT and CHT SoCs is then provided. Therefore, in this albeit unusual > > > > > instance, I reason is it appropriate to set HDMI_LPE_AUDIO so that > > audio > > > > is > > > > > automatically provided regardless of distribution. If a distributor > > > > didn't > > > > > want to allow audio for BYT and CHT SoC based devices running their > > > > distro > > > > > then they could always remove it from their distro specific config. > > > > > > > > It's a wrong approach. What we're discussing about is just a > > > > configuration for a new individual driver, and the same rule should be > > > > applied to it like others. > > > > > > > > Check other drivers. See whether default=y (or =m) is set to > > > > CONFIG_E1000E, as a random example. With your argument, it should be > > > > set to y or m as default, since the Ethernet functionality is already > > > > provided by the network core. > > > > > > > > In general, we don't set the default values to the driver configs > > > > unless there is a VERY specific reason to do so. > > > > > > > > > > > I'm trying to get HDMI audio by default for BYT & CHT SoC but currently > > > this requires 'CONFIG_HDMI_LPE_AUDIO' set with a value of 'm'. I don't > > want > > > to argue a 'special case' or promote a 'wrong approach' but just get HDMI > > > audio working so is there another way to achieve this? > > > > What's wrong with manually setting CONFIG_HDMI_LPE_AUDIO=m or =y? > > IOW, do all features on your CHT/BYT machines work without adjusting > > manually after defconfig? If you have to do it in anyway, what makes > > it special for HDMI_LPD_AUDIO? > > > > > I've just tested various scenarios using a variety of devices with > v4.11-rc3. Having CONFIG_HDMI_LPE_AUDIO set by default is sufficient to get > audio on BYT/CHT devices over HDMI. > > For example installing Ubuntu 16.04.2 on a BYT/CHT device, then upgrading > the kernel to v4.11-rc3 using the deb-binary from http://kernel.ubuntu.com/~ > kernel-ppa/mainline/v4.11-rc3/ (an example of a current distro which is > compiling without setting CONFIG_HDMI_LPE_AUDIO) and there is no audio over > HDMI. Alternatively downloading v4.11-rc3 source, making defconfig, > manually setting CONFIG_HDMI_LPE_AUDIO, compiling and installing the > kernel on the BYT/CHT device will give you audio over HDMI. > > If the BYT/CHT device has other sound cards (e.g accessed via a headphone > jack) then audio without setting CONFIG_HDMI_LPE_AUDIO may be possible > depending on the codec used and whether it is provided by default in the > kernel. So for example a Tronsmart Ara (CHT) device has audio over > headphones using the pre-compiled deb-binary above but no audio over HDMI. > Whereas with a (1st gen) Intel Compute Stick (BYT) device no audio is > possible using the pre-compiled deb-binary as the device only has an HDMI > port. To get sound you must therefore currently use a self-compiled kernel > with CONFIG_HDMI_LPE_AUDIO set. > > Whilst Canonical may set CONFIG_HDMI_LPE_AUDIO to provide audio on BYT/CHT > devices by when is unknown and there is no guarantee they actually will. > > This will be similar for all other distros with the worst case scenario > that no distributor adds CONFIG_HDMI_LPE_AUDIO to their configs resulting > in (arguably) little point including HDMI LPE audio support in the kernel. > > I've laboured the point about 'BYT/CHT devices audio over HDMI' but to > answer your question completely there are other BYT/CHT devices (typically > tablets) that need a whole other bunch of patches to fix this and that. > They may need specialist kernel configs with specific settings but that is > a separate issue to the basic functional need of having audio over HDMI. > > Does the above explanation justify my current approach or is there an > alternative that can be considered? Sorry, no, you've explained how much you love the HDMI audio, but it doesn't answer my question clearly. My question is simple: are *all* features the upstream kernel supports for your device now (e.g. input, network or whatever) enabled by the pure arch/x86/configs/x86_64_defconfig *without* manually setting the configs to y or m? I bet you likely have to set some configs there manually to m or y. Then, if the manual selection for such missing configs is acceptable, what makes the HDMI audio so special and it must be set to y/m as default, while other devices aren't set like that...? That's the question. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
