Hi Tomi,
we are trying to find out why the low power communication with the ssd2858 rotator chip
is unreliable.
My last test was to boot the OMAP5432EVM, start the rotator with the panel-mipi-debug driver
and just send generic read packets to the ssd (to read out a register value) in a loop. The shell
script speed appears to be one packet every 6ms. There is no high speed video stream enabled.
This sequence did succeed ~10 times and then failed:
[ 52.880569] dsi: mipi_debug_reset(0)
[ 57.342784] dsi: mipi_debug_regulator(1)
[ 64.613874] dsi: mipi_debug_reset(1)
[ 76.991831] x_res=1280
[ 76.994491] y_res=720
[ 76.997052] dsi: mipi_debug_start()
[ 77.001041] dsi: mipi_debug_power_on()
[ 77.014577] dsi: enabled()
[ 95.800064] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.806605] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.812807] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.818963] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.825080] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.831298] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.837691] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.843805] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.849950] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.856059] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 95.862200] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 02
[ 96.366686] omapdss DSI error: Failed to receive BTA
[ 96.371901] omapdss DSI error: DSI error, irqstatus 100010
[ 96.377759] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 96.876725] omapdss DSI error: Failed to receive BTA
[ 96.881939] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 97.386659] omapdss DSI error: Failed to receive BTA
[ 97.391875] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 97.896653] omapdss DSI error: Failed to receive BTA
[ 97.901863] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 98.406643] omapdss DSI error: Failed to receive BTA
[ 98.411862] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 98.916677] omapdss DSI error: Failed to receive BTA
[ 98.921890] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 99.426620] omapdss DSI error: Failed to receive BTA
[ 99.431840] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 99.936594] omapdss DSI error: Failed to receive BTA
[ 99.941803] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 100.446674] omapdss DSI error: Failed to receive BTA
[ 100.451894] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 100.956567] omapdss DSI error: Failed to receive BTA
[ 100.961783] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
[ 101.466561] omapdss DSI error: Failed to receive BTA
[ 101.471781] dsi: mipi_debug_read(g, 00 04) -> 00 00 00 00 failed: -5
Using an Oscilloscope I could see some packets on the DSI lane 1
as expected, but what I wonder is why I see silence (LP-11 state) after
the first BTA/DSI error.
This means that the OMAP5 stops any transmission. Is this expected
behaviour of the DSI driver?
And I usually need to reboot the EVM to get out of this state. So can we
somehow “reset” the DSI subsystem to the initial state without reboot?
BR,
Nikolaus