Re: The failure summary report of GEN2 for linux stable v4.10-rc2

[Hiep Cao Minh <cm-hiep@jinso.co.jp>]

Hello Laurent,
Thanks for your feedback.

Sorry for the late reply.


>>> Thank you. I think I know what's wrong. The default mode picked by the
>>> system in your case uses positive H/V sync polarities, while in my cases
>>> the sync signals have negative polarities. Could you try to select
>>> 1024x768 @60Hz instead of 1024x768 @75Hz ? I think the HDMI output would
>>> then work correctly, which would confirm that the problem is indeed
>>> caused by sync polarities.
>> Dong is sick, so he did not attend today. He will reply to you tomorrow.
>> Could you explain more how to set 1024x768 @60Hz and negative polarities
>> for the HDMI output?,
> I've investigated the problem further here now that I'm back home with access
> to my Lager board, but have been unable to reproduce it even by testing all
> sync signal polarities.
>
> First of all, the "CMA enabled" kernel configuration file attached to a
> previous e-mail in this series indeed enables CMA, but doesn't enable CMA
> usage for DMA buffers. You need to additionally set
>
> CONFIG_DMA_CMA=y
> CONFIG_CMA_SIZE_MBYTES=128
>
> The amount of CMA memory to reserve can vary depending on the tests you
> perform. The larger the resolutions and the number of buffers are, the more
> memory you will need. 128MB should be a safe bet for most cases. Feel free to
> reduce that if you need to use a lot of memory outside of CMA, or increase it
> if you run into buffer allocation failures with multimedia devices (DU, VIN,
> VSP, ...). You can then let the HDMI cable plugged at all time and you should
> not get framebuffer allocation failures when booting the board with the cable
> plugged in.
>
> Then, I tried to modify the H/V sync polarities by using different video
> modes. If you look at the output of "modetest -M rcar-du", you should get a
> list of modes similar to the following for the HDMI output.
>
> 1440x900  60 1440 1520 1672 1904  900  903  909  934 flags: nhsync, pvsync
> 1280x1024 75 1280 1296 1440 1688 1024 1025 1028 1066 flags: phsync, pvsync
> 1280x1024 60 1280 1328 1440 1688 1024 1025 1028 1066 flags: phsync, pvsync
> 1440x900  75 1440 1536 1688 1936  900  903  909  942 flags: nhsync, pvsync
> 1280x800  60 1280 1328 1360 1440  800  803  809  823 flags: phsync, nvsync
> 1152x864  75 1152 1216 1344 1600  864  865  868  900 flags: phsync, pvsync
> 1024x768  75 1024 1040 1136 1312  768  769  772  800 flags: phsync, pvsync
> 1024x768  70 1024 1048 1184 1328  768  771  777  806 flags: nhsync, nvsync
> 1024x768  60 1024 1048 1184 1344  768  771  777  806 flags: nhsync, nvsync
> 832x624   75  832  864  928 1152  624  625  628  667 flags: nhsync, nvsync
> 800x600   75  800  816  896 1056  600  601  604  625 flags: phsync, pvsync
> 800x600   72  800  856  976 1040  600  637  643  666 flags: phsync, pvsync
> 800x600   60  800  840  968 1056  600  601  605  628 flags: phsync, pvsync
> 800x600   56  800  824  896 1024  600  601  603  625 flags: phsync, pvsync
> 640x480   75  640  656  720  840  480  481  484  500 flags: nhsync, nvsync
> 640x480   73  640  664  704  832  480  489  492  520 flags: nhsync, nvsync
> 640x480   67  640  704  768  864  480  483  486  525 flags: nhsync, nvsync
> 640x480   60  640  656  752  800  480  490  492  525 flags: nhsync, nvsync
> 720x400   70  720  738  846  900  400  412  414  449 flags: nhsync, pvsync
>
> Each mode has a defined horizontal and vertical polarity. If you pick your
> modes carefully you will be able to test all four combinations of polarities.
> I tried them all, and couldn't reproduce the reported problem with the test
> procedure that Dong specified.
>
> The easiest way to select a video mode for the fbdev compatibility layer is to
> specify it as the default mode on the kernel command line using the video=
> argument. The mode value is in the form of <width>x<height>@<refresh rate>.
> For instance, to select the 1024x768 75Hz mode, simply add
>
> 	video=1024x768@75
>
> to the kernel command line arguments (there are multiple ways to do so
> depending on how you configured your boot loader, I personally like to modify
> the bootargs value in the .dts file for the board).
>
> Could you please check if the problem occurs with all video modes supported by
> your HDMI monitor or with some of them only ?
>
We have tried to configure our test environment based on your 
explanation, then tested it again.
But It didn't work. (we tried all of video parameters 
<width>x<height>@<refresh rate> we have )
And we tried to confirm the issue on Simon's tree of renesas-backport 
bsp v3.10.31-rcar-gen2-1.9.9.
It worked with the same test method.

Did you check the issue on Upstream mainline version? or your own tree?
Could you attach your config file?
I was wondering that your config and ours might be different.

Thank you.
Hiep.