> Am 06.11.2017 um 17:00 schrieb Tomi Valkeinen <tomi.valkeinen@xxxxxx>: > > On 06/11/17 16:04, H. Nikolaus Schaller wrote: >> Hi, >> some time after upgrading to 4.14-rc* I tried to boot the OpenPandora. >> It turned out that the display panel has a bug - it only shows black/blue colors >> instead of RGB. >> >> Some tests revealed that something happened between 4.13.0 and 4.14-rc1. >> Here are screen photos: >> >> 4.13.0: http://download.goldelico.com/letux-kernel/files/thumb_DSC00812_1024.jpeg >> 4.14-rc1: http://download.goldelico.com/letux-kernel/files/thumb_DSC00813_1024.jpeg >> >> But only for the OpenPandora. For the GTA04 it works. >> >> Well, the GTA04 is using a different panel "toppoly,td028ttec1" >> and driver instead of "omapdss,tpo,td043mtea1". >> [BTW: there seems to be some mixup of "compatible" schemes]. > > Omapdss boot-time code will prepend the compatibles with "omapdss,". The > point is that the DTS is generic, but we'll still end up matching with > the omapdss specific drivers. It's a temporary hack, and gets dropped as > soon as we can use the common DRM panel model. > >> And there is also another difference between both: the Pandora 600MHz uses an >> OMAP3530 while the GTA04 uses a DM3730. >> >> So something has become incompatible with *some* DPI panel drivers. >> >> After more than a week of bisecting in parallel to important other tasks >> (it takes ca. 30-60 minutes for each run to add local patches, compile, >> install, boot, check results - just to find some "[drm:omap_crtc_error_irq] *ERROR* lcd: errors: 00004000"), >> I ended up with a specific result: >> >> >> iMac:master hns$ git bisect bad >> d178e034d5653edfbd16d0c71eeeed467e33c96f is the first bad commit >> commit d178e034d5653edfbd16d0c71eeeed467e33c96f >> Author: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> >> Date: Sat Aug 5 01:44:12 2017 +0300 >> >> drm: omapdrm: Move FEAT_DPI_USES_VDDS_DSI feature to dpi code >> >> The FEAT_DPI_USES_VDDS_DSI feature is specific to the DPI, move it from >> the omap_dss_features structure to the dpi code. > > Well, the patch is simple enough... For some reason, the > soc_device_match(dpi_soc_devices) call there doesn't match Pandora. Ok, I think I have found it. The pattern in dpi_soc_devices[] is wrong. Here is what my printk hack() reports on the 600 MHz Pandora (OMAP3530): [ 20.171325] soc_device_match_attr() [ 20.175445] attr [ 20.177398] machine = OMAP3430/3530 [ 20.181274] family = OMAP3 [ 20.184295] revision = ES3.1 [ 20.188232] soc_id = null [ 20.191192] match [ 20.193237] machine = null [ 20.196411] family = OMAP3[456]* [ 20.199981] revision = null [ 20.203124] soc_id = null [ 20.182403] dpi_init_regulator() match Changing the pattern to "OMAP[3456]*" makes it work but I am not sure what exactly is intended. Should the pattern match the .machine and not the .family? The DM3730 based GTA04 reports (without patch): [ 18.618621] soc_device_match_attr() [ 18.622314] attr [ 18.624237] machine = OMAP3630/DM3730 [ 18.628509] family = OMAP3 [ 18.631561] revision = ES1.2 [ 18.634765] soc_id = null [ 18.638000] match [ 18.640014] machine = null [ 18.643035] family = OMAP3[456]* [ 18.646697] revision = null [ 18.649810] soc_id = null [ 18.652770] soc_device_match_attr() [ 18.656616] attr [ 18.658538] machine = OMAP3630/DM3730 [ 18.662567] family = OMAP3 [ 18.665649] revision = ES1.2 [ 18.668853] soc_id = null [ 18.671813] match [ 18.673828] machine = null [ 18.677001] family = [AD]M37* [ 18.680297] revision = null [ 18.683410] soc_id = null [ 18.686614] dpi_init_regulator() no match Here we have no match and don't enable VDDS_DSI - but it still works (maybe VDDS_DSI is enabled elsewhere). And I do not see how the second pattern .family = "[AD]M37*" can ever match. According to the comment in the original patch: "The DPI uses the DSI VDDS on OMAP34xx, OMAP35xx, OMAP36xx, AM37xx and DM37xx only." a single match for .family = "OMAP3" should suffice. Shouldn't it? And there is no family "AM/DM37*". Or is it? A tiny and subtle flaw which has such a strange result... But I don't know what would be correct. BR and thanks, Nikolaus -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
