On 2019-09-12 at 14:23:05 +0000, Harry Wentland wrote: > On 2019-09-12 3:47 a.m., Ramalingam C wrote: > > On 2019-09-09 at 15:54:50 +0000, Lakha, Bhawanpreet wrote: > >> Hi all, > >> > >> This is regarding the recent hdcp content type patch that was merged into > >> drm-misc. > >> (https://patchwork.freedesktop.org/patch/320958/?series=57233&rev=11) > >> > >> There are displays on the market that advertise HDCP 2.2 support and will > >> pass authentication and encryption but will then show a > >> corrupted/blue/black screen (the driver cannot detect this). These > >> displays work with HDCP 1.4 without any issues. Due to the large number of > >> HDCP-supporting devices on the market we might not be able to catch them > >> with a blacklist. > >> > >> From the user modes perspective, HDCP1.4 and HDCP2.2 Type0 are the same > >> thing. Meaning that this interface doesn't allow us to force the hdcp > >> version. Due to the problems mentioned above we might want to expose the > >> ability for a user to force an HDCP downgrade to a certain level (e.g. > >> 1.4) in case they experience problems. > >> > >> What are your thoughts? and what would be a good way to deal with it? > > Hi, > > > > As you mentioned, uAPI is designed to be HDCP version agnostic. Kernel > > supposed to exercise the highest version of HDCP supported on panel and > > platform. > > > > As we implement the HDCP spec support, if a device is non-compliant with > > HDCP spec after completing the HDCP authentication, I dont think we need > > to worry about it. > > > > Tell that to our (or your) customers. > > In this case an enduser might plug in a bad monitor or TV and be unable > to play protected content. > > What if we add a new enum value to the content_type property that says > "DRM_MODE_HDCP_CONTENT_TYPE_FORCE_14"? "content type" is for defining the stream type. Adding an entry into it sounds like polluting it.
Separate uAPI for forcing a HDCP version might be need. Or wondering on using the sysfs of connector for this dirty job!? -Ram > > Harry > > > In case if you want to track and implement a quirk for it, like not to > > project the HDCP2.2 capability, you can use the receiver id of that panel > > to track it. > > > > Thanks, > > -Ram > >> > >> > >> Thanks, > >> > >> Bhawan _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
