Hi Marek, Am Dienstag, 23. Mai 2023, 15:10:05 CEST schrieb Marek Vasut: > On 5/23/23 13:17, Alexander Stein wrote: > > Hello Marek, > > Hi, > > > Am Montag, 15. Mai 2023, 18:24:24 CEST schrieb Marek Vasut: > >> Add TC9595 DSI-to-DPI and DSI-to-(e)DP bridge to > >> DH electronics i.MX8M Plus DHCOM SoM . The bridge > >> is populated on the SoM, but disabled by default > >> unless used for display output. > >> > >> Signed-off-by: Marek Vasut <marex@xxxxxxx> > > > > Were you actually able to access the display? E.g. reading DPCD via AUX > > channel? > > I only tried the full display port (the one with large plug) on the TC > evaluation kit, there I could use the aux channel. Are you testing this > bridge and running into issues ? Details please ? Which SoC is this evaluation kit based on? Yes, I'm trying to test this bridge on imx8mp based board. AFAICS I run into a timeout during drm connector .get_modes call, see kernel log below. > samsung-dsim 32e60000.dsi: [drm:samsung_dsim_host_attach [samsung_dsim]] Attached tc358767 device > tc358767 1-000f: failed to read DPCD: -110 > tc358767 1-000f: failed to read display props: -110 Looking at the AUX_CH+/- signals, I can see the native aux request and the (presumable) correct answer (DP_DPCD_REV register) from the display. But for some reason the bridge runs into a aux timeout. I can see in the DP0_AUXSTATUS register the bus gets busy (0x1) after starting transfer. But after the tc_aux_wait_busy() call DP0_AUXSTATUS his indicating a timeout and sync error (0x310002). When changing the "Aux Bit Period Calculator Threshold" to 5 (register AUXCFG1), the sync error is gone, but the timeout still happens. The frequency used from the display is ~1MHz, which should be okay. So on the electrical side all seems okay, but the native aux transfer don't work. Any ideas? Best regards, Alexander -- TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany Amtsgericht München, HRB 105018 Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider http://www.tq-group.com/
