Even though data is truncated to 24 bits, the I2S interface does
accept 32 bit data (the slot widths according to the data sheet
can be 16 or 32 bits) so let the hw_params callback reflect this,
even if the lowest 8 bits are not used when 32 bits are specified.
This is normally how 24 bit audio data is handled (i.e. as 32 bit
data, with the LSB:s unused) and this is also reflected in other
bridge drivers which handle audio, for instance sii902x.c and
synopsis/dw-hdmi-i2s-audio.c .
Signed-off-by: Ricard Wanderlof <[email protected]>
---
drivers/gpu/drm/bridge/adv7511/adv7511_audio.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_audio.c b/drivers/gpu/drm/bridge/adv7511/adv7511_audio.c
index 61f4a38e7d2b..4563f5d8136f 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_audio.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_audio.c
@@ -101,11 +101,14 @@ static int adv7511_hdmi_hw_params(struct device *dev, void *data,
case 20:
len = ADV7511_I2S_SAMPLE_LEN_20;
break;
- case 32:
- if (fmt->bit_fmt != SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE)
- return -EINVAL;
- fallthrough;
case 24:
+ case 32:
+ /*
+ * 32 bits are handled like 24 bits, except that the lowest
+ * 8 bits are discarded. In fact, the accepted I2S slot widths
+ * are 16 and 32 bits, so the chip is fully compatible with
+ * 32 bit data.
+ */
len = ADV7511_I2S_SAMPLE_LEN_24;
break;
default:
--
2.30.2
On Tue, May 28, 2024 at 12:04:49PM +0200, Ricard Wanderlof wrote:
>
> Even though data is truncated to 24 bits, the I2S interface does
> accept 32 bit data (the slot widths according to the data sheet
> can be 16 or 32 bits) so let the hw_params callback reflect this,
> even if the lowest 8 bits are not used when 32 bits are specified.
>
> This is normally how 24 bit audio data is handled (i.e. as 32 bit
> data, with the LSB:s unused) and this is also reflected in other
> bridge drivers which handle audio, for instance sii902x.c and
> synopsis/dw-hdmi-i2s-audio.c .
>
> Signed-off-by: Ricard Wanderlof <[email protected]>
> ---
> drivers/gpu/drm/bridge/adv7511/adv7511_audio.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
Reviewed-by: Dmitry Baryshkov <[email protected]>
What about:
Fixes: ae053fa234f4 ("drm: bridge: adv7511: Support I2S IEC958 encoded PCM format")
?
--
With best wishes
Dmitry
On Tue, 28 May 2024, Dmitry Baryshkov wrote:
> On Tue, May 28, 2024 at 12:04:49PM +0200, Ricard Wanderlof wrote:
> >
> > Even though data is truncated to 24 bits, the I2S interface does
> > accept 32 bit data (the slot widths according to the data sheet
> > can be 16 or 32 bits) so let the hw_params callback reflect this,
> > even if the lowest 8 bits are not used when 32 bits are specified.
> ...
> > ---
> > drivers/gpu/drm/bridge/adv7511/adv7511_audio.c | 11 +++++++----
> > 1 file changed, 7 insertions(+), 4 deletions(-)
> >
>
> Reviewed-by: Dmitry Baryshkov <[email protected]>
>
> What about:
>
> Fixes: ae053fa234f4 ("drm: bridge: adv7511: Support I2S IEC958 encoded PCM format")
>
> ?
IMHO, commit ae053fa234f4 doesn't break anything, so there's nothing to be
fixed. It adds S/PDIF support, which uses a 32 bit format, but the 32 bit
format was not supported at all prior to that commit.
I don't really have a problem adding the Fixes tag if you think it's
useful, but it doesn't seem quite right to me.
/Ricard
--
Ricard Wolf Wanderlof ricardw(at)axis.com
Axis Communications AB, Lund, Sweden http://www.axis.com
Phone +46 46 272 2016 Fax +46 46 13 61 30
On Thu, May 30, 2024 at 09:17:03AM +0200, Ricard Wanderlof wrote:
>
> On Tue, 28 May 2024, Dmitry Baryshkov wrote:
>
> > On Tue, May 28, 2024 at 12:04:49PM +0200, Ricard Wanderlof wrote:
> > >
> > > Even though data is truncated to 24 bits, the I2S interface does
> > > accept 32 bit data (the slot widths according to the data sheet
> > > can be 16 or 32 bits) so let the hw_params callback reflect this,
> > > even if the lowest 8 bits are not used when 32 bits are specified.
> > ...
> > > ---
> > > drivers/gpu/drm/bridge/adv7511/adv7511_audio.c | 11 +++++++----
> > > 1 file changed, 7 insertions(+), 4 deletions(-)
> > >
> >
> > Reviewed-by: Dmitry Baryshkov <[email protected]>
> >
> > What about:
> >
> > Fixes: ae053fa234f4 ("drm: bridge: adv7511: Support I2S IEC958 encoded PCM format")
> >
> > ?
>
> IMHO, commit ae053fa234f4 doesn't break anything, so there's nothing to be
> fixed. It adds S/PDIF support, which uses a 32 bit format, but the 32 bit
> format was not supported at all prior to that commit.
Agreed, let's keep it out of the question.
>
> I don't really have a problem adding the Fixes tag if you think it's
> useful, but it doesn't seem quite right to me.
>
> /Ricard
> --
> Ricard Wolf Wanderlof ricardw(at)axis.com
> Axis Communications AB, Lund, Sweden http://www.axis.com
> Phone +46 46 272 2016 Fax +46 46 13 61 30
--
With best wishes
Dmitry