On Fri, 08 Dec 2023, Matt Roper matthew.d.roper@intel.com wrote:
On Fri, Dec 08, 2023 at 01:20:08PM +0200, Jani Nikula wrote:
Unless I'm completely misreading the bspec, there are no defined bits for plane gtt fault errors in DE PIPE IIR for a display versions 12-14. This would explain why DG2 in the linked bug is getting thousands of fault errors.
I think you might be misreading the spec? On TGL, bits 7-11 are listed as plane1-4+cursor fault status, and bits 20-22 are listed as plane 5-7 fault status. Bits 7-11 are tagged with a REMOVEDBY tag that eventually drops them for MTL onward, and bits 20-22 are tagged with a REMOVEDBY tag that drops them for RKL onward (which makes sense because those extra planes stopped existing at that point).
Maybe the bspec's way of displaying things is what's causing the confusion? When you see
REMOVEDBY(xxxx) [ Foo, Bar, Baz ]The "Foo, Bar, Baz" platform list is the *remaining* list of platforms after the removal is taken into account, not the platforms actually being removed. You can hover over the REMOVEDBY link to see the actual platforms being removed and a link to the change record for that.
Yeah. It's not one of the more clear register specs out there. Sorry for the noise, and thanks for taking the time to explain this.
BR, Jani.