* Re: [PATCH] drm/bridge: dw-hdmi-i2s: set insert_pcuv bit if hardware supports it
[not found] ` <YwOEPpO0gux+njQe@sirena.org.uk>
@ 2022-08-22 14:35 ` Geraldo Nascimento
2022-08-23 14:46 ` Geraldo Nascimento
1 sibling, 0 replies; 3+ messages in thread
From: Geraldo Nascimento @ 2022-08-22 14:35 UTC (permalink / raw)
To: Mark Brown; +Cc: Sugar Zhang, ALSA-devel, Kuninori Morimoto
On Mon, Aug 22, 2022 at 02:27:26PM +0100, Mark Brown wrote:
> On Sat, Aug 20, 2022 at 09:36:53PM -0300, Geraldo Nascimento wrote:
>
> > + /*
> > + * dw-hdmi introduced insert_pcuv bit in version 2.10a.
> > + * When set (1'b1), this bit enables the insertion of the PCUV
> > + * (Parity, Channel Status, User bit and Validity) bits on the
> > + * incoming audio stream (support limited to Linear PCM audio)
> > + */
> > +
> > + if (hdmi_read(audio, HDMI_DESIGN_ID) >= 0x21)
> > + conf2 |= HDMI_AUD_CONF2_INSERT_PCUV;
>
> So what if we're not handlign linear PCM?
Good question, Mark. For HBR and NL-PCM there are different bits that
need to be set in aud_conf2 Sample Register, and then insert_pcuv bit
needs to be dropped.
I don't have a sink handy however to test the other modes. Do you have
a suggestion on how to make this the default for L-PCM specifically?
Thanks,
Geraldo Nascimento
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] drm/bridge: dw-hdmi-i2s: set insert_pcuv bit if hardware supports it
[not found] ` <YwOEPpO0gux+njQe@sirena.org.uk>
2022-08-22 14:35 ` [PATCH] drm/bridge: dw-hdmi-i2s: set insert_pcuv bit if hardware supports it Geraldo Nascimento
@ 2022-08-23 14:46 ` Geraldo Nascimento
2022-08-23 16:20 ` Mark Brown
1 sibling, 1 reply; 3+ messages in thread
From: Geraldo Nascimento @ 2022-08-23 14:46 UTC (permalink / raw)
To: Mark Brown; +Cc: Sugar Zhang, ALSA-devel, Kuninori Morimoto
On Mon, Aug 22, 2022 at 02:27:26PM +0100, Mark Brown wrote:
> On Sat, Aug 20, 2022 at 09:36:53PM -0300, Geraldo Nascimento wrote:
>
> > + /*
> > + * dw-hdmi introduced insert_pcuv bit in version 2.10a.
> > + * When set (1'b1), this bit enables the insertion of the PCUV
> > + * (Parity, Channel Status, User bit and Validity) bits on the
> > + * incoming audio stream (support limited to Linear PCM audio)
> > + */
> > +
> > + if (hdmi_read(audio, HDMI_DESIGN_ID) >= 0x21)
> > + conf2 |= HDMI_AUD_CONF2_INSERT_PCUV;
>
> So what if we're not handlign linear PCM?
Hi Mark,
I think we may be able to restrict the fix for L-PCM only by checking
byte 0 of iec.status, specifically bit 1. Our define is called
IEC958_AES0_NONAUDIO but https://tech.ebu.ch/docs/tech/tech3250.pdf
calls it the "Linear PCM identification" bit. There's also a
supplement to AES/EBU 3250 in https://tech.ebu.ch/docs/n/n009_1.pdf
Let me know if the following is OK. I'll be happy to submit V2 if
it is.
Thanks,
Geraldo Nascimento
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
@@ -42,6 +42,7 @@ static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
struct dw_hdmi *hdmi = audio->hdmi;
u8 conf0 = 0;
u8 conf1 = 0;
+ u8 conf2 = 0;
u8 inputclkfs = 0;
/* it cares I2S only */
@@ -101,6 +102,18 @@ static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
return -EINVAL;
}
+ /*
+ * dw-hdmi introduced insert_pcuv bit in version 2.10a.
+ * When set (1'b1), this bit enables the insertion of the PCUV
+ * (Parity, Channel Status, User bit and Validity) bits on the
+ * incoming audio stream (support limited to Linear PCM audio)
+ */
+
+ if (hdmi_read(audio, HDMI_DESIGN_ID) >= 0x21 &&
+ !(hparms->iec.status[0] & IEC958_AES0_NONAUDIO))
+ conf2 = HDMI_AUD_CONF2_INSERT_PCUV;
+
dw_hdmi_set_sample_rate(hdmi, hparms->sample_rate);
dw_hdmi_set_channel_status(hdmi, hparms->iec.status);
dw_hdmi_set_channel_count(hdmi, hparms->channels);
@@ -109,6 +122,7 @@ static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
hdmi_write(audio, inputclkfs, HDMI_AUD_INPUTCLKFS);
hdmi_write(audio, conf0, HDMI_AUD_CONF0);
hdmi_write(audio, conf1, HDMI_AUD_CONF1);
+ hdmi_write(audio, conf2, HDMI_AUD_CONF2);
return 0;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] drm/bridge: dw-hdmi-i2s: set insert_pcuv bit if hardware supports it
2022-08-23 14:46 ` Geraldo Nascimento
@ 2022-08-23 16:20 ` Mark Brown
0 siblings, 0 replies; 3+ messages in thread
From: Mark Brown @ 2022-08-23 16:20 UTC (permalink / raw)
To: Geraldo Nascimento; +Cc: Sugar Zhang, ALSA-devel, Kuninori Morimoto
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On Tue, Aug 23, 2022 at 11:46:38AM -0300, Geraldo Nascimento wrote:
> I think we may be able to restrict the fix for L-PCM only by checking
> byte 0 of iec.status, specifically bit 1. Our define is called
> IEC958_AES0_NONAUDIO but https://tech.ebu.ch/docs/tech/tech3250.pdf
> calls it the "Linear PCM identification" bit. There's also a
> supplement to AES/EBU 3250 in https://tech.ebu.ch/docs/n/n009_1.pdf
> Let me know if the following is OK. I'll be happy to submit V2 if
> it is.
LGTM, though I don't really know anything about the hardware
specifically.
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^ permalink raw reply [flat|nested] 3+ messages in thread
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[not found] ` <YwOEPpO0gux+njQe@sirena.org.uk>
2022-08-22 14:35 ` [PATCH] drm/bridge: dw-hdmi-i2s: set insert_pcuv bit if hardware supports it Geraldo Nascimento
2022-08-23 14:46 ` Geraldo Nascimento
2022-08-23 16:20 ` Mark Brown
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