Quoting Kuogee Hsieh (2022-01-24 13:24:25) > > On 1/24/2022 1:04 PM, Stephen Boyd wrote: > > Quoting Kuogee Hsieh (2022-01-24 12:46:10) > >> Some of DP link compliant test expects to return fail-safe mode > >> if prefer detailed timing mode can not be supported by mainlink's > >> lane and rate after link training. Therefore add fail-safe mode > >> into connector mode list as backup mode. This patch fixes test > >> case 4.2.2.1. > >> > >> Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> > > Any Fixes tag? I also wonder why this isn't pushed into the DP core code > > somehow. Wouldn't every device need to add a 640x480 mode by default? > > Original test case 4.2.2.1 always passed until we did firmware upgrade > of our compliance test tester (Unigraph) recently. Ok. So the Fixes tag should be the introduction of the driver or at least whenever compliance testing support was added. > > The new firmware of tester use newer edid contains 1080p with 145.7 mhz > which can not be supported by 2 lanes with 1.6G rate. Hence we failed > this test case. Interesting. So the test case wouldn't fail unless the number of lanes were limited by the hardware? Seems that the test isn't thorough. > > After discuss with Vendor, they claims we have to return fail-safe mode > if prefer detailed timing mode can not be supported. > > I think would be good to add fail-safe mode into connector mode list. > > > > > > we just run into this problem recently. Sure I'm not saying it's incorrect, just wondering why a connector that's DP wouldn't have the 640x480 resolution by default somewhere in the drm core.
