On 11/15/16 19:36, Bartosz Golaszewski wrote: > 2016-11-14 17:54 GMT+01:00 Jyri Sarha <jsarha@xxxxxx>: >> Adds drm bride support for attaching drm bridge drivers to tilcdc. The >> decision whether a video port leads to an external encoder or bridge >> is made simply based on remote device's compatible string. The code >> has been tested with BeagleBone-Black with and without BeagleBone >> DVI-D Cape Rev A3 using ti-tfp410 driver. >> >> Signed-off-by: Jyri Sarha <jsarha@xxxxxx> >> --- > > Hi Jyri, > > thanks a lot for doing this. > > One issue I see with this patch is that tilcdc doesn't seem to support > deferred probe correctly (if modules are built-in). The following > happens on my setup: > > The dump-vga-dac module is loaded first, but the i2c0 is not ready yet > - probe returns EPROBE_DEFER and it's propagated to tilcdc probe. > > [drm] Initialized > dumb-vga-dac vga_bridge: Couldn't retrieve i2c bus > > Then the i2c bus is initialized and dump-vga-dac probe succeeds, but > the second probe of tilcdc gives me: > > [drm:drm_debugfs_init] *ERROR* Cannot create /sys/kernel/debug/dri/64 > [drm:drm_minor_register] *ERROR* DRM: Failed to initialize > /sys/kernel/debug/dri. > tilcdc: probe of da8xx_lcdc.0 failed with error -1 > > I was able to work around this issue by loading modules in correct order. > Did you have any conflicts when applying my patch? I have done quite a few changes lately and especially the initialization sequence and back off from deferred probe may get broken easily broken if the source base is not correct. I try to come up with a pull-request candidate branch soon (hopefully tomorrow) for you to test. > I then tried testing the patch with a da850-lcdk, but I don't get > anything on the display (no signal), even though the LCDC seems to > work fine (modetest and dmesg messages work just like when using the > tilcdc panel). Also: I see the EDID info is correctly retrieved from > the display. > > Could you take a look at my DT[1] and see if you find it correct? > It is hard to follow the dts diff, but if it probes and tilcdc is able to read EDID modes, there should not be anything more to it. Cheers, Jyri > Best regards, > Bartosz Golaszewski > > [1] http://pastebin.com/dfUX7PyL > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
