linux-kernel - Re: [PATCH v3 1/1] drm: sun4i: hdmi: Add support for sun4i HDMI encoder audio

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Message-ID: <64676a4b-e149-146c-81b4-7fd5e792efc5@olimex.com>
Date:   Thu, 30 Jan 2020 08:20:55 +0200
From:   Stefan Mavrodiev <stefan@...mex.com>
To:     Maxime Ripard <maxime@...no.tech>,
        Stefan Mavrodiev <stefan@...mex.com>
Cc:     Chen-Yu Tsai <wens@...e.org>, David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        open list <linux-kernel@...r.kernel.org>,
        "open list:DRM DRIVERS FOR ALLWINNER A10" 
        <dri-devel@...ts.freedesktop.org>,
        "moderated list:ARM/Allwinner sunXi SoC support" 
        <linux-arm-kernel@...ts.infradead.org>,
        linux-sunxi@...glegroups.com
Subject: Re: [PATCH v3 1/1] drm: sun4i: hdmi: Add support for sun4i HDMI
 encoder audio

Hi,

On 1/29/20 6:43 PM, Maxime Ripard wrote:
> Hi,
>
> On Tue, Jan 28, 2020 at 04:06:42PM +0200, Stefan Mavrodiev wrote:
>> diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
>> index 68d4644ac2dc..4cd35c97c503 100644
>> --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
>> +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
>> @@ -23,6 +23,8 @@
>>   #include <drm/drm_print.h>
>>   #include <drm/drm_probe_helper.h>
>>
>> +#include <sound/soc.h>
>> +
>>   #include "sun4i_backend.h"
>>   #include "sun4i_crtc.h"
>>   #include "sun4i_drv.h"
>> @@ -87,6 +89,10 @@ static void sun4i_hdmi_disable(struct drm_encoder *encoder)
>>
>>   	DRM_DEBUG_DRIVER("Disabling the HDMI Output\n");
>>
>> +#ifdef CONFIG_DRM_SUN4I_HDMI_AUDIO
>> +	sun4i_hdmi_audio_destroy(hdmi);
>> +#endif
>> +
>>   	val = readl(hdmi->base + SUN4I_HDMI_VID_CTRL_REG);
>>   	val &= ~SUN4I_HDMI_VID_CTRL_ENABLE;
>>   	writel(val, hdmi->base + SUN4I_HDMI_VID_CTRL_REG);
>> @@ -114,6 +120,11 @@ 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);
>> +
>> +#ifdef CONFIG_DRM_SUN4I_HDMI_AUDIO
>> +	if (hdmi->hdmi_audio && sun4i_hdmi_audio_create(hdmi))
>> +		DRM_ERROR("Couldn't create the HDMI audio adapter\n");
>> +#endif
> I really don't think we should be creating / removing the audio card
> at enable / disable time.

For me it's unnatural to have sound card all the time, even when the HDMI
is not plugged-in.

I'll follow your suggestion. Besides it's easier for me just to drop this
register/unregister mechanism.

Best regards,
Stefan Mavrodiev

>
> To fix the drvdata pointer, you just need to use the card pointer in
> the unbind, and that's it.
>
> Maxime