Hi Christian, On 12/6/25 9:27 AM, Christian Hewitt wrote: > From: Jonas Karlman <[email protected]> > > Channel Allocation (PB4) and Level Shift Information (PB5) are > configured with values from PB1 and PB2 due to the wrong offset > being used. This results in missing audio channels or incorrect > speaker placement when playing multi-channel audio. > > Use the correct offset to fix multi-channel audio output. > > Fixes: fd0141d1a8a2 ("drm/bridge: synopsys: Add audio support for dw-hdmi-qp") > Reported-by: Christian Hewitt <[email protected]> > Signed-off-by: Jonas Karlman <[email protected]> > > --- > buffer is a pointer to u8 while data written to PKT_AUDI_CONTENTS > is u32, so buffer contains audio infoframe header (buffer[0:2]) + > checksum (buffer[3]) + payload byte 1-10 (buffer[4:13]), e.g. > > regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS1, &buffer[3], 1) > .. will write PB0-PB3 to AUDI_CONTENTS1 > > regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS2, &buffer[4], 1) > .. will write PB1-PB4 to AUDI_CONTENTS2, but should be PB4-PB7 > > &buffer[4] will point to payload byte 4 not payload byte 1, due > to u8/u32 and not considering the size of header+checksum (3+1). > --- > drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c > index f3a13da488e6..7b8a69383dc4 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c > @@ -845,7 +845,7 @@ static int dw_hdmi_qp_config_audio_infoframe(struct > dw_hdmi_qp *hdmi, > > regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS0, &header_bytes, 1); > regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS1, &buffer[3], 1); > - regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS2, &buffer[4], 1); > + regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS2, &buffer[7], 1);
Since making use of regmap_bulk_write(), this could be further optimized as: - regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS1, &buffer[3], 1); - regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS2, &buffer[4], 1); + regmap_bulk_write(hdmi->regm, PKT_AUDI_CONTENTS1, &buffer[3], 2); Regardless, Reviewed-by: Cristian Ciocaltea <[email protected]> Please note you also need to provide your SoB, check "Sign your work ..." section in [1]. Regards, Cristian [1] https://www.kernel.org/doc/Documentation/process/submitting-patches.rst
