SPI noisy signal when connected to level shifter

[rosen1]

Continuing the discussion from SPI Level Shifter from 3,3V to 5V:

So , the level shifter did work, but with Raspberry, I tested all of the hardware separately and Ii found out that , the moment I connect a level shifter to the Jetson I becomme a really noisy signal around 1,6V. I can’t explain it to myself.

Another problem i saw is when the jetson is not connected to the level shifter. I wanted to test the SPI. I noticed that when slave select is down, the data is sent really fast for really small amount of time and in the rest of it , nothing is done as in the image.

Blue signal is SCK
Yellow is Slave Select
A reference from the Raspberry with the same Code and Wiring

[ShaneCCC]

Could you try below patch to confirm it.

diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index 9a4abb4..2aadf42 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -1490,10 +1490,8 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
                msg->actual_length += xfer->len;

 complete_xfer:
-               if (prefer_last_used_cs)
                        cmd1 = tspi->command1_reg;
-               else
-                       cmd1 = tspi->def_command1_reg;
+
                if (ret < 0 || skip) {
                        if (cstate && cstate->cs_gpio_valid)
                                gpio_set_value(spi->cs_gpio, gval);