Jetson nano production module emmc

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hi,

I have followed all the forum posts in order to get our custom board sdcard working,
I am left with the final issue, after a hardreboot everything is fine,
After a softreboot (sudo reboot) i get many errors from the emmc (same as i saw in other posts)
Anyway i have attempted to add nvidia,vmmc-always-on like it said in the other posts,
But its either not working or i am not placing the nvidia,vmmc-always-on in the correct DTS file
Please can you specify exactly to which DTS file and the location in the the file that I should the nvidia,vmmc-always-on.

Thanks

3

Add to the sdhci scope like below

sdhci@3400000 {
 		mmc-ocr-mask = <0x0>;
 		cd-gpios = <&tegra_main_gpio TEGRA194_MAIN_GPIO(G, 7) 0>;
 		nvidia,cd-wakeup-capable;
 		nvidia,vmmc-always-on;
 		status = "okay";
 	};
4

Its working now, no issues after soft reboot

Thanks Shane.

6

hi shane,

The softreboot issue has returned. I get emmc errors again when performing softreboot .

The issue is as following:

when i add max-clk-limit = <400000> to the sdhci@700b0400 scope, there are no emmc errors but the read/write rates from the SD card are very low.
If i remove the max-clk-limit = <400000> i get the emmc errors when i perform softreboot.

Please specify the changes I need to apply to the DTS file in order to solve this problem.

Here is the DTS file:
tegra210-porg-p3448-common.zip (5.7 KB)

Thanks

7

What’s if modify the value as below?

max-clk-limit = <199680000>

8

I have tried it with your solution and also many values in max-clk-limit and it still didnt work.

Anyway, I have noticed that when I perform power cycle and ran dmesg, I saw the following messages :
.
.
[ 1.842452] mmc1: SDHCI controller on sdhci-tegra.2 [sdhci-tegra.2] using ADMA 64-bit with 64 bit addr
.
.
[ 1.907874] mmc1: host does not support reading read-only switch, assuming write-enable
.
.
[ 2.057052] mmc1: Tuning correction cannot be applied
[ 2.057075] mmc1: hw tuning done …
[ 2.057185] mmc1: new ultra high speed SDR104 SDHC card at address aaaa
.
.

It looks like that in hardreboot a hardware tuning is being done.

But when I perform software reset and run dmesg, I didnt see the hw tuning line:
.
.
[ 1.898276] mmc1: SDHCI controller on sdhci-tegra.2 [sdhci-tegra.2] using ADMA 64-bit with 64 bit addr
.
.
[ 1.942074] mmc1: host does not support reading read-only switch, assuming write-enable
.
.
[ 1.946669] mmc1: new high speed SDHC card at address aaaa
.
.

Is there a way to force an emmc hardware tuning when performing software reboot?

Here are the two dmesg logs:
after power cycle:
dmesg_After_Power_Cycle.txt (63.9 KB)

after software reboot:
dmesg_After_Software_Reboot.txt (72.0 KB)

Thanks

10

hello ben.r,

please access TX1 TRM, you should refer to [Table 200: Maximum Data Transfer Speeds (eMMC)] for reference.
thanks