hello, this mail just to report an experience about using the DRM driver on sun7i (Olimex A20 SOM EVB). let me start thanking all the guys doing the "heavylifting" for this feature/driver.
*TL;DR* i'll be very synthetic, it starts to work (you can see a picture, then some minutes later screen shuts off) albeit it's still a hard to gain feature as lot's of info is scattered here and there or implicit, that's why i try to recap here the simpler recipe to "see the light".. first i've got the* 4.9rc7 kernel* runnng from sunxi-next git tree: https://github.com/linux-sunxi/linux-sunxi/commits/sunxi-next i compiled with the default defconfig for this Olimex A20 SOM EVB board and booted. i've got *simplefb* working; as the FB was working since uboot phase, thanx to this "modeline": CONFIG_VIDEO_LCD_MODE="x:800,y:480,depth:24,pclk_khz:33000,le:45,ri:209,up:22,lo:22,hs:1,vs:1,sync:3,vmode:0" then i added in DTS the extended lines as from this commit by "net147" (thanx): https://github.com/net147/linux/commit/cd93810d8a565d2348e27756f4bb2762dc6cc79d BTW i added in *drivers/gpu/drm/panel/panel-simple.c* the setup of my panel (a noname 800x480 7inch working in uboot), and put accordingly the panel's compatible entry in place of the *lcd-olinuxino-43-ts* in DTS: ... panel: panel { compatible = "olimex,lcd-olinuxino-43-ts"; ... then i had to patch kernel for "relaxing" the panel *clock validation step* with this very recent "hack" for the clock matching: http://www.spinics.net/lists/kernel/msg2390747.html and this is more or less everything to see the DRM LCD working on A20 in *dmesg* the relevant lines are: --- [ 1.082842] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). [ 1.082846] [drm] No driver support for vblank timestamp query. [ 1.083328] sun4i-drm display-engine: bound 1e60000.display-backend (ops 0xc063d87c) [ 1.083841] sun4i-drm display-engine: bound 1c0c000.lcd-controller (ops 0xc063d410) [ 1.083886] checking generic (7fe89000 177000) vs hw (0 ffffffff) [ 1.083890] fb: switching to sun4i-drm-fb from simple [ 1.137201] Console: switching to colour dummy device 80x30 and this is all fantastic. i could display fancy images with *fbv* (i'm working on straight framebuffer, no X), thanks to all those involved. the only issue is that, after few minutes (10 or so), the display switch to this kind of rendering: https://drive.google.com/open?id=0B9QRW6Oy0GmeOGdvM3YyYUtqZHM no messages on syslog or console. i'm wondering which kind of "glitch" could bring to this (i suppose some kind of "clock power down"?). maybe setting up some *DRM debug level,* could bring to helpful messages. i'll check how to enable those, if any has suggestions, are welcome. later, i'd like to test the mali binary libraries as net147 tells they works too (i'll test ES GL on plain framebuffer and not X) . i see this kernel open sorce low level driver compiles (adding some setup on *build.sh*): https://github.com/mripard/sunxi-mali but i'm stopping on adding the relevant entry in the DTS. and this is the topic for another report, eventually. Andrea -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
