| Message ID | 20240529100301.127652-1-sebastian.wick@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | edid-decode: Cannot support NonMixed MS without MS | expand |
Hi Sebastian, On 29/05/2024 12:02, Sebastian Wick wrote: > When `Max Stream Count` is zero, the sink does not support multistream > and thus cannot support NonMixed MS. > > An EDID with Max Stream Count = 0 and Non Mixed MS = 1 can be found in > linuxhw/EDID ./Digital/TCL/TCL5655/1723FF2DC6D1 at commit cff7fe4d44. > > Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com> > --- > parse-cta-block.cpp | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git ./parse-cta-block.cpp ../parse-cta-block.cpp > index 4d2afc6..7cd7a3a 100644 > --- ./parse-cta-block.cpp > +++ ../parse-cta-block.cpp > @@ -2498,10 +2498,11 @@ static void cta_hdmi_audio_block(const unsigned char *x, unsigned length) > fail("Empty Data Block with length %u.\n", length); > return; > } > - if (x[0] & 3) > + if (x[0] & 3) { > printf(" Max Stream Count: %u\n", (x[0] & 3) + 1); > - if (x[0] & 4) > - printf(" Supports MS NonMixed\n"); > + if (x[0] & 4) > + printf(" Supports MS NonMixed\n"); > + } I would actually leave this as-is, but instead add a fail() message if MS NonMixed is set, but Max Stream Count == 0. It's really an EDID conformity failure, and it should be reported as such. Regards, Hans > > num_descs = x[1] & 7; > if (num_descs == 0)
On Wed, May 29, 2024 at 4:16 PM Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote: > > Hi Sebastian, > > On 29/05/2024 12:02, Sebastian Wick wrote: > > When `Max Stream Count` is zero, the sink does not support multistream > > and thus cannot support NonMixed MS. > > > > An EDID with Max Stream Count = 0 and Non Mixed MS = 1 can be found in > > linuxhw/EDID ./Digital/TCL/TCL5655/1723FF2DC6D1 at commit cff7fe4d44. > > > > Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com> > > --- > > parse-cta-block.cpp | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > diff --git ./parse-cta-block.cpp ../parse-cta-block.cpp > > index 4d2afc6..7cd7a3a 100644 > > --- ./parse-cta-block.cpp > > +++ ../parse-cta-block.cpp > > @@ -2498,10 +2498,11 @@ static void cta_hdmi_audio_block(const unsigned char *x, unsigned length) > > fail("Empty Data Block with length %u.\n", length); > > return; > > } > > - if (x[0] & 3) > > + if (x[0] & 3) { > > printf(" Max Stream Count: %u\n", (x[0] & 3) + 1); > > - if (x[0] & 4) > > - printf(" Supports MS NonMixed\n"); > > + if (x[0] & 4) > > + printf(" Supports MS NonMixed\n"); > > + } > > I would actually leave this as-is, but instead add a fail() message > if MS NonMixed is set, but Max Stream Count == 0. > > It's really an EDID conformity failure, and it should be reported as such. I'm all for adding a fail() message but I'm afraid our implementation which tries to be compatible with the output here won't have access to the MS NonMixed bit when Max Stream Count == 0. Would this work for you? if (x[0] & 3) { printf(" Max Stream Count: %u\n", (x[0] & 3) + 1); if (x[0] & 4) printf(" Supports MS NonMixed\n"); else fail("NonMixed MS support indicated but MS is unsupported\n"); } > > Regards, > > Hans > > > > > num_descs = x[1] & 7; > > if (num_descs == 0) >
On 04/06/2024 18:57, Sebastian Wick wrote: > On Wed, May 29, 2024 at 4:16 PM Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote: >> >> Hi Sebastian, >> >> On 29/05/2024 12:02, Sebastian Wick wrote: >>> When `Max Stream Count` is zero, the sink does not support multistream >>> and thus cannot support NonMixed MS. >>> >>> An EDID with Max Stream Count = 0 and Non Mixed MS = 1 can be found in >>> linuxhw/EDID ./Digital/TCL/TCL5655/1723FF2DC6D1 at commit cff7fe4d44. >>> >>> Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com> >>> --- >>> parse-cta-block.cpp | 7 ++++--- >>> 1 file changed, 4 insertions(+), 3 deletions(-) >>> >>> diff --git ./parse-cta-block.cpp ../parse-cta-block.cpp >>> index 4d2afc6..7cd7a3a 100644 >>> --- ./parse-cta-block.cpp >>> +++ ../parse-cta-block.cpp >>> @@ -2498,10 +2498,11 @@ static void cta_hdmi_audio_block(const unsigned char *x, unsigned length) >>> fail("Empty Data Block with length %u.\n", length); >>> return; >>> } >>> - if (x[0] & 3) >>> + if (x[0] & 3) { >>> printf(" Max Stream Count: %u\n", (x[0] & 3) + 1); >>> - if (x[0] & 4) >>> - printf(" Supports MS NonMixed\n"); >>> + if (x[0] & 4) >>> + printf(" Supports MS NonMixed\n"); >>> + } >> >> I would actually leave this as-is, but instead add a fail() message >> if MS NonMixed is set, but Max Stream Count == 0. >> >> It's really an EDID conformity failure, and it should be reported as such. > > I'm all for adding a fail() message but I'm afraid our implementation > which tries to be compatible with the output here won't have access to > the MS NonMixed bit when Max Stream Count == 0. > > Would this work for you? > > if (x[0] & 3) { > printf(" Max Stream Count: %u\n", (x[0] & 3) + 1); > if (x[0] & 4) > printf(" Supports MS NonMixed\n"); > else > fail("NonMixed MS support indicated but MS is unsupported\n"); > } Correcting the logic that would be this: if (x[0] & 3) { printf(" Max Stream Count: %u\n", (x[0] & 3) + 1); if (x[0] & 4) printf(" Supports MS NonMixed\n"); } else if (x[0] & 4) { fail("MS NonMixed support indicated but Max Stream Count == 0.\n"); } And that works for me. Regards, Hans > >> >> Regards, >> >> Hans >> >>> >>> num_descs = x[1] & 7; >>> if (num_descs == 0) >> >
diff --git ./parse-cta-block.cpp ../parse-cta-block.cpp index 4d2afc6..7cd7a3a 100644 --- ./parse-cta-block.cpp +++ ../parse-cta-block.cpp @@ -2498,10 +2498,11 @@ static void cta_hdmi_audio_block(const unsigned char *x, unsigned length) fail("Empty Data Block with length %u.\n", length); return; } - if (x[0] & 3) + if (x[0] & 3) { printf(" Max Stream Count: %u\n", (x[0] & 3) + 1); - if (x[0] & 4) - printf(" Supports MS NonMixed\n"); + if (x[0] & 4) + printf(" Supports MS NonMixed\n"); + } num_descs = x[1] & 7; if (num_descs == 0)
When `Max Stream Count` is zero, the sink does not support multistream and thus cannot support NonMixed MS. An EDID with Max Stream Count = 0 and Non Mixed MS = 1 can be found in linuxhw/EDID ./Digital/TCL/TCL5655/1723FF2DC6D1 at commit cff7fe4d44. Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com> --- parse-cta-block.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)