Re: [PATCH 07/11] edid-decode: always linefeed after hex_block

[Joe van Tunen <joevt@shaw.ca>]

Yes, that's ugly. I will do a search for the EDID that prompted me to make this change. Maybe it's not a problem anymore.
...
Seems like the problem I had was fixed in cta_hdr10plus. I'll do more checking and testing with other calls to hex_block.


On 2021-09-15, 3:10 AM, "Hans Verkuil" <hverkuil@xs4all.nl> wrote:

    On 14/09/2021 14:11, joevt wrote:
    > hex_block should not return without printing a newline (which occurs when the length is zero). This causes a missing newline after "Application Version: 1" with cta_hdr10plus for an EDID I have.
    > Any place that calls hex_block will have the same problem if it's possible for the length to be zero.
    > 
    > In other words, a hex_block needs to have a linefeed even if it has zero length, because the caller assumes it will go to the next line as it does when the hex block is not zero length.
    > 
    > Signed-off-by: Joe van Tunen <joevt@shaw.ca>
    > ---
    >  edid-decode.cpp | 4 +++-
    >  1 file changed, 3 insertions(+), 1 deletion(-)
    > 
    > diff --git a/edid-decode.cpp b/edid-decode.cpp
    > index 2316abc..6aa93fb 100644
    > --- a/edid-decode.cpp
    > +++ b/edid-decode.cpp
    > @@ -698,8 +698,10 @@ void hex_block(const char *prefix, const unsigned char *x,
    >  {
    >  	unsigned i, j;
    >  
    > -	if (!length)
    > +	if (!length) {
    > +		printf("\n");
    >  		return;
    > +	}

    Hmm, with this change I get this:

    edid-decode -c Digital/Acer/ACR0282/B12D637C1F12 with the linuxhw database:

      Vendor-Specific Data Block (HDMI), OUI 00-0C-03:
        Source physical address: 2.0.0.0
      Unknown CTA-861 tag 0x00, length 0

      Unknown CTA-861 tag 0x00, length 0

      Unknown CTA-861 tag 0x00, length 0

      Unknown CTA-861 tag 0x00, length 0

      Unknown CTA-861 tag 0x00, length 0

      Unknown CTA-861 tag 0x00, length 0

      Unknown CTA-861 tag 0x00, length 0

    That looks pretty ugly.

    Regards,

    	Hans

    >  
    >  	for (i = 0; i < length; i += step) {
    >  		unsigned len = min(step, length - i);
    >