Hi Stefan, On Tue, Jan 14, 2020 at 11:04:55AM +0200, Stefan Mavrodiev wrote: > On 1/10/20 6:26 PM, Maxime Ripard wrote: > > Hi, > > > > On Fri, Jan 10, 2020 at 04:11:40PM +0200, Stefan Mavrodiev wrote: > > > Add HDMI audio support for the sun4i-hdmi encoder, used on > > > the older Allwinner chips - A10, A20, A31. > > > > > > Most of the code is based on the BSP implementation. In it > > > dditional formats are supported (S20_3LE and S24_LE), however > > > there where some problems with them and only S16_LE is left. > > > > > > Signed-off-by: Stefan Mavrodiev > > > --- > > > drivers/gpu/drm/sun4i/Kconfig | 1 + > > > drivers/gpu/drm/sun4i/Makefile | 1 + > > > drivers/gpu/drm/sun4i/sun4i_hdmi.h | 30 ++ > > > drivers/gpu/drm/sun4i/sun4i_hdmi_audio.c | 375 +++++++++++++++++++++++ > > > drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 4 + > > > 5 files changed, 411 insertions(+) > > > create mode 100644 drivers/gpu/drm/sun4i/sun4i_hdmi_audio.c > > > > > > diff --git a/drivers/gpu/drm/sun4i/Kconfig b/drivers/gpu/drm/sun4i/Kconfig > > > index 37e90e42943f..192b732b10cd 100644 > > > --- a/drivers/gpu/drm/sun4i/Kconfig > > > +++ b/drivers/gpu/drm/sun4i/Kconfig > > > @@ -19,6 +19,7 @@ if DRM_SUN4I > > > config DRM_SUN4I_HDMI > > > tristate "Allwinner A10 HDMI Controller Support" > > > default DRM_SUN4I > > > + select SND_PCM_ELD > > > help > > > Choose this option if you have an Allwinner SoC with an HDMI > > > controller. > > > diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile > > > index 0d04f2447b01..e2d82b451c36 100644 > > > --- a/drivers/gpu/drm/sun4i/Makefile > > > +++ b/drivers/gpu/drm/sun4i/Makefile > > > @@ -5,6 +5,7 @@ sun4i-frontend-y += sun4i_frontend.o > > > sun4i-drm-y += sun4i_drv.o > > > sun4i-drm-y += sun4i_framebuffer.o > > > > > > +sun4i-drm-hdmi-y += sun4i_hdmi_audio.o > > > sun4i-drm-hdmi-y += sun4i_hdmi_ddc_clk.o > > > sun4i-drm-hdmi-y += sun4i_hdmi_enc.o > > > sun4i-drm-hdmi-y += sun4i_hdmi_i2c.o > > > diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi.h b/drivers/gpu/drm/sun4i/sun4i_hdmi.h > > > index 7ad3f06c127e..456964e681b0 100644 > > > --- a/drivers/gpu/drm/sun4i/sun4i_hdmi.h > > > +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi.h > > > @@ -42,7 +42,32 @@ > > > #define SUN4I_HDMI_VID_TIMING_POL_VSYNC BIT(1) > > > #define SUN4I_HDMI_VID_TIMING_POL_HSYNC BIT(0) > > > > > > +#define SUN4I_HDMI_AUDIO_CTRL_REG 0x040 > > > +#define SUN4I_HDMI_AUDIO_CTRL_ENABLE BIT(31) > > > +#define SUN4I_HDMI_AUDIO_CTRL_RESET BIT(30) > > > + > > > +#define SUN4I_HDMI_AUDIO_FMT_REG 0x048 > > > +#define SUN4I_HDMI_AUDIO_FMT_SRC BIT(31) > > > +#define SUN4I_HDMI_AUDIO_FMT_LAYOUT BIT(3) > > > +#define SUN4I_HDMI_AUDIO_FMT_CH_CFG(n) (n - 1) > > There's the issue multiple times in the headers, but you should wrap n > > in parentheses to make sure we have no issue with precedence when > > calling the macro. > > > > > +int sun4i_hdmi_audio_create(struct sun4i_hdmi *hdmi) > > > +{ > > > + struct snd_soc_card *card = &sun4i_hdmi_audio_card; > > > + struct snd_soc_dai_link_component *comp; > > > + struct snd_soc_dai_link *link; > > > + int ret; > > > + > > > + ret = devm_snd_dmaengine_pcm_register(hdmi->dev, > > > + &sun4i_hdmi_audio_pcm_config, 0); > > > + if (ret) { > > > + DRM_ERROR("Could not register PCM\n"); > > > + return ret; > > > + } > > > + > > > + ret = devm_snd_soc_register_component(hdmi->dev, > > > + &sun4i_hdmi_audio_component, > > > + &sun4i_hdmi_audio_dai, 1); > > > + if (ret) { > > > + DRM_ERROR("Could not register DAI\n"); > > > + return ret; > > > + } > > > + > > > + link = devm_kzalloc(hdmi->dev, sizeof(*link), GFP_KERNEL); > > > + if (!link) > > > + return -ENOMEM; > > > + > > > + comp = devm_kzalloc(hdmi->dev, sizeof(*comp) * 3, GFP_KERNEL); > > > + if (!comp) > > > + return -ENOMEM; > > > + > > > + link->cpus = &comp[0]; > > > + link->codecs = &comp[1]; > > > + link->platforms = &comp[2]; > > > + > > > + link->num_cpus = 1; > > > + link->num_codecs = 1; > > > + link->num_platforms = 1; > > > + > > > + link->playback_only = 1; > > > + > > > + link->name = "SUN4I-HDMI"; > > > + link->stream_name = "SUN4I-HDMI PCM"; > > > + > > > + link->codecs->name = dev_name(hdmi->dev); > > > + link->codecs->dai_name = sun4i_hdmi_audio_dai.name; > > > + > > > + link->cpus->dai_name = dev_name(hdmi->dev); > > > + > > > + link->platforms->name = dev_name(hdmi->dev); > > > + > > > + link->dai_fmt = SND_SOC_DAIFMT_I2S; > > > + > > > + card->dai_link = link; > > > + card->num_links = 1; > > > + card->dev = hdmi->dev; > > > + > > > + snd_soc_card_set_drvdata(card, hdmi); > > > + return devm_snd_soc_register_card(hdmi->dev, card); > > > > Out of curiosity, did you try to remove the module with that patch > > applied? IIRC, these functions will overwrite the device drvdata, and > > we will try to access them in unbind / remove. > > Actually I did not. Just tried that and you're right. The module > crashes at the unbind call. I use sun4i_hdmi struct only for > regmap. Maybe create separate private structure and copy only > regmap? I think the issue is that: - In bind, we first call dev_set_drvdata on the bound device, with a pointer to struct sun4i_hdmi as the value. The driver_data field in struct device is now a pointer to our instance of struct sun4i_hdmi. - In audio create, you then call snd_soc_card_set_drvdata with a pointer to struct sun4i_hdmi as the value. The drvdata field in the struct snd_soc_card is now a pointer to our instance of struct sun4i_hdmi (so far so good). - Then you call (devm_)snd_soc_register_card. One of the thing that it will do is call drv_set_drvdata on the card->dev device, setting it to our pointer to the struct snd_soc_card we provided. However, since you set card->dev to the same device than the one initially bound, this means that you just overwrote the struct sun4i_hdmi pointer with a pointer to struct snd_soc_card. - The driver will operate properly, since we never really use the driver_data field, in the HDMI driver, except when... - At unbind, you retrieve the driver_data field, expecting a struct sun4i_hdmi pointer, except you have a pointer to struct snd_soc_card, and everything explodes. I think the way to work around that would be to create a new (platform_)device for the HDMI audio component, so that ASoC can work on that device instead. This seems to be what dw-hdmi is doing here: https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c#L2812 (Except that they are also using platform_data, since they have multiple drivers, we wouldn't, so we can just lookup sun4i_hdmi using the parent's device driver_data). > > > +} > > > diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c > > > index a7c4654445c7..79ecd89fb705 100644 > > > --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c > > > +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c > > > @@ -114,6 +114,9 @@ static void sun4i_hdmi_enable(struct drm_encoder *encoder) > > > val |= SUN4I_HDMI_VID_CTRL_HDMI_MODE; > > > > > > writel(val, hdmi->base + SUN4I_HDMI_VID_CTRL_REG); > > > + > > > + if (hdmi->hdmi_audio && sun4i_hdmi_audio_create(hdmi)) > > > + DRM_ERROR("Couldn't create the HDMI audio adapter\n"); > > > > So you create the audio card each time the display is enabled? I guess > > this is to deal with the hotplug? > > Yes. See below. > > > I'm not sure this is the right thing to do. If I remember well, the > > ELD are here precisely to let userspace know that the display is > > plugged (and audio-capable) or not. > > > > Also, you don't remove that card in the disable, which mean that if > > you end up in a situation where you would enable the display, disable > > it and then enable it again, you have two audio cards now. > > There is issue with the hotplug. When inserting the cable, the event > is detected and the hdmi encoder is enabled. Thus the card is > created. However further removal and insertions are not > detected. I guess we would need to fix that then? > This is why I don't remove the card. > > Also I count on devm_snd_soc_register_card() to release the card. I think you should really create the card all the time, and just update the ELD to let the userspace know when something has been created. And yeah, we should have a working hotplug, but that's a separate story :) Maxime