Hi Nikolaus,
On Tuesday, 7 November 2017 13:36:14 EET H. Nikolaus Schaller wrote:
Am 06.11.2017 um 17:00 schrieb Tomi Valkeinen tomi.valkeinen@ti.com:
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.jpe g 4.14-rc1: http://download.goldelico.com/letux-kernel/files/thumb_DSC00813_1024.jpe g
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@ideasonboard.com 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?
I think that would work. It would additionally match the TI814x, but that SoC doesn't seem to have a DSS anyway.
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.
As explained in a patch in another e-mail in this thread, the match should have been against machine, not family. We could either test that patch, or just match against machine = "OMAP3", which would be simpler.
Tomi, do you know any OMAP3 machine that doesn't use the DSI VDDS for DPI ?