DS90UB941AS-Q1: Unstable link with forward channel dsi + back channel i2c and GPIO

Prodigy 90 points

Replies: 7

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Part Number: DS90UB941AS-Q1

Hello, 

We are using DS90UB941/DS90UB948 with LVDS display.

We are using 4lane dsi(input port1) and data on LVDS display is OK. 

reg dump of Ser-Des, 

i2cdump -y -f 2 0x1a
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 34 00 00 8a 00 00 58 50 50 01 ab 01 07 35 35 03 4..?..XPP????55?
10: 00 00 00 ff 00 00 fe 1e 7f 7f 01 00 04 00 01 00 ...?..?????.?.?.
20: 0b 00 25 00 00 00 00 00 01 20 20 b8 00 00 a5 5a ?.%.....? ?..?Z
30: 00 09 00 05 0c 00 00 00 00 00 00 00 00 00 81 02 .?.??.........??
40: 10 90 00 00 00 00 00 00 00 00 00 00 00 00 00 ac ??.............?
50: 16 00 00 00 02 10 00 02 00 00 d9 81 07 06 44 42 ?...??.?..????DB
60: 22 02 00 00 10 00 00 00 00 00 00 00 00 02 20 00 "?..?........? .
70: 78 ba a0 00 00 00 00 78 ba a0 00 00 00 00 80 00 x??....x??....?.
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
c0: 00 00 82 00 38 00 00 64 40 00 00 00 00 02 ff 00 ..?.8..d@....??.
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
e0: 00 00 82 00 28 08 00 00 00 00 00 00 00 02 00 00 ..?.(?.......?..
f0: 5f 55 42 39 34 31 00 00 00 00 00 00 00 00 00 00 _UB941..........

i2cdump -y -f 2 0x2c
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 58 04 00 f0 fe 9e 00 34 00 00 00 00 00 00 00 00 X?.???.4........
10: 00 00 00 00 00 00 00 00 00 01 01 00 03 13 53 05 .........??.??S?
20: 00 00 40 28 08 00 83 84 01 00 00 00 00 00 00 00 ..@(?.???.......
30: 00 00 90 25 01 00 00 9e 00 00 00 05 20 e0 23 00 ..?%?..?...? ?#.
40: 43 03 03 00 60 88 00 00 0f 82 00 08 00 00 63 00 C??.`?..??.?..c.
50: 03 10 00 01 80 00 00 00 00 7f 20 20 00 00 00 00 ??.??....? ....
60: 00 00 00 00 10 00 00 00 00 00 00 00 00 00 01 00 ....?.........?.
70: 00 00 00 07 07 08 00 00 00 00 00 00 02 00 00 00 ...???......?...
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
a0: 00 00 8c 00 00 00 00 00 00 00 00 00 00 00 00 00 ..?.............
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
c0: 00 00 00 00 00 00 00 00 c0 00 00 00 00 00 00 00 ........?.......
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
f0: 5f 55 42 39 34 38 00 00 00 00 00 00 00 00 00 00 _UB948..........

But with the event of interrupt(GPIO0) and i2c read to the slave device, Display is flickering and the link pin on UB948 is not stable.

We are not seeing any flickering in display when color bar enabled on the UB941. We have issue only when UB941 is processing DSI inputs. 

Any settings on UB941 can solve this issue?

Regards,

Manoj

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