On Mon, Aug 1, 2022 at 3:07 PM Adam Ford [off-list ref] wrote:

On Mon, Aug 1, 2022 at 2:33 PM Fabio Estevam [off-list ref] wrote:

quoted

Hi Adam,

On Sat, Jul 30, 2022 at 12:16 PM Adam Ford [off-list ref] wrote:

quoted

Hey all,

I am trying to test Jagan's patch series [1] to add support for the
samsung dsim bridge which is used on the imx8mm to output DSI video.
The DSIM gets the video from the mxsfb, and in my case, the DSI is
sent to the adv7535 for connecting to HDMI.

I had to add some extra patches on top of Jagan's imx8mm-dsi-v3 to get
HDMI output functional on a imx8mm-evk via ADV7535:

https://github.com/fabioestevam/kernel/commits/imx8mm-dsi-v3

Does it work on your board?

Fabio,

I tried your branch, but I still get no video on the output of HDMI.
I do get a response to the modetest.  I won't post the whole thing
here, but here is a snippet

CRTCs:
id fb pos size
33 37 (0,0) (1920x1080)
  #0 1920x1080 60.00 1920 2008 2052 2200 1080 1084 1089 1125 148500
flags: nhsync, nvsync; type: driver
  props:
24 VRR_ENABLED:
flags: range
values: 0 1
value: 0

Planes:
id crtc fb CRTC x,y x,y gamma size possible crtcs
31 33 37 0,0 0,0 0        0x00000001
  formats: RG16 XR24
  props:
8 type:
flags: immutable enum
enums: Overlay=0 Primary=1 Cursor=2
value: 1
30 IN_FORMATS:
flags: immutable blob
blobs:

value:
01000000000000000200000018000000
01000000200000005247313658523234
03000000000000000000000000000000
0000000000000000
in_formats blob decoded:
RG16:  LINEAR
XR24:  LINEAR

Frame buffers:
id size pitch

When I compare this with NXP's downstream kernel that works with this
monitor, I get some different info:

CRTCs:
id fb pos size
33 41 (0,0) (1920x1080)
  #0 1920x1080 60.00 1920 2008 2052 2200 1080 1084 1089 1125 148500
flags: nhsync, nvsync; type: driver
  props:
24 VRR_ENABLED:
flags: range
values: 0 1
value: 0

Planes:
id crtc fb CRTC x,y x,y gamma size possible crtcs
31 33 41 0,0 0,0 0        0x00000001
  formats: XR24 AR24 RG16 XB24 AB24 RX24 RA24 AR15 XR15 AB15 XB15 BG16
  props:
8 type:
flags: immutable enum
enums: Overlay=0 Primary=1 Cursor=2
value: 1
32 zpos:
flags: immutable range
values: 0 0
value: 0

Frame buffers:
id size pitch

Notably, the  formats for the downstream list significantly more
formats.  I don't know how that translates to working video, but it
was something to note.

I'll give them a try tonight.  I managed to get a hold of an adv7535
user manual, and there are some items that it appears NXP did in their
downstream kernel that never got pushed upstream. Based on my review
of some of the changes, some of the NXP changes seem reasonable to me.
If/when I can get it working, I'll try to report back some of my
findings and push driver changes to the adv7535 as I find them.

adam

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