Hi ,
We have developed a custom base board based on nano SOM . In which we haveSD card as a peripheral , normal class 4 high speed sd card is detected properly .But when we connect an UHS 1 SD card , we are getting and error stated below and the card is not even detected. mmc1: error -110 whilst initialising SD card
I have added below the the dtb properties I have used.Please let me know If I have missed something.
Hi wayne,
The board doesnt have a SDMMC_VDD_EN .But the same base board detects UHS card with the folloing spec with xavier nx SOM,
clock: 208000000 Hz
vdd: 21 (3.3 ~ 3.4 V)
bus mode: 2 (push-pull)
chip select: 0 (don’t care)
power mode: 2 (on)
bus width: 2 (4 bits)
timing spec: 6 (sd uhs SDR104)
signal voltage: 1 (1.80 V)
driver type: 0 (driver type B)
However the read and write speeds are low in NX,
WRITE_SPEED : 28.7 MB/s
READ_SPEED : 27.0 MB/s
But the UHS SD is not even detected in Nano, whereas the other high speed class 4 sd cards are detcted.I tried with rel-32.4.3, as you suggested and that doesn’t work out .And also I tried the patch and dtb change you mentioned , that too doesnt work out.
Also I would like to add that I get these prints in u-boot in nano .Pllease check if it could help you,
MMC: no card present
** Bad device mmc 1 **
I have two questions,
1)The speed of UHS card I mentioned in NX is low .I need to know if this is the normal behaviour or not
2)I have wired for SDMMC_VDD_EN.What change should I do in dtb for that.Where should I mention the gpio that I have wired.
will definitely try the patch that you have mentioned.But it looks like the patch is for NX.
As you have asked to summarize the issues,
1)UHS1 SD not detected in Nano.
2)UHS1 SD detected with SD104 in NX, but the speeds are low ,as I have mentioned earlier.(nearly 25 MBps)
Both the SOMs are tested on version of same base board designed by us.
Hi ,
I currently dont have access to xavier Nx SOM , will check that on monday.
Regd., the card not detected issue on UHS Nano, I have tried with different cards and could you please show a sample of dtb with vmmc-supply added one.I am asking this because I tried this and didn’t work.
This is how it was added in NX dtb,
vmmc-supply = <&p3668_vdd_sdmmc1_sw>;
and p3668_vdd_sdmmc1_sw has its defenition in hardware/nvidia/platform/t19x/jakku/kernel-dts/common/tegra194-fixed-regulator-p3668.dtsi
Should I add a similar entry in nano too ?
Yes, you have to. You have to write a similar regulator and assign this regulator to the vmmc-supply.
If this is still not clear to you, try to search keyword “p3448_vdd_3v3_sd” in the device tree folder and write similar one.
I have added the gpio C,4 in p3448_vdd_3v3_sd which I have wired . We are using a sandisk UHS-1 card.Please let us know if it is a problem with the a specific card vendor.Also we get a debug message
“mmc1: error -110 whilst initialising SD card”
Please check if this could help in any way in debugging.