Hi,
We use sdmmc3 to have a sd card extension.
Now tested 4/8/32/64 Gb TF cards of Sandisk, seems ok for lower speed.
The only one is we have a card with class10 level and 32Gb TF caused sys reboot.
What we did is just enable sdmmc3 in dts config about software.
Anyone could give some advices.
Is the hw design bad ?
Or something to do with sw, for example to decrese the clock of sdmmc ?
And how/where to config the clock of sdmmc in dtsi ?
The basic device tree change for enabling sdmmc3
https://forums.developer.nvidia.com/t/microsd-card-not-detected-on-jetson-nano-production-module/80776/14
if sdmmc speed is slow. you need the patch here
https://forums.developer.nvidia.com/t/slow-sd-card-access-speed-read-write-with-jetson-nano-production-module/111749/31
if tires warm boot, the speed becomes slow again. Need to add this patch in kernel
https://forums.developer.nvidia.com/t/jetson-nano-sd-card-enters-back-to-high-speed-mode-instead-of-uhs-mode-after-soft-reboot/119041/4
if you don’t have SDMMC_VDD_EN gpio on their carrier board, then need to add “nvidia,vmmc-always-on” under sdhci device tree.
And lacking of (4) is a bad design that may have side effect.
Hi WayneWWW,
thanks for your response,
for now:
BTW, could you tell me how to reduce the clock of sdmmc3 ?
What we need focus on now is that we can’t let system panic reboot.
thanks.
Please apply them all first.
Hi,
ok, thanks.
Another issue Nano pwm0 cant work , could you or is there anyone give some help?
@WayneWWW
Hi，thanks for response.
I had resolved the issue by increase the clock limit.
Could you share the patch you’ve done here so that other users can take as a reference?
@WayneWWW
Here the patch.
BTW, i tested with tf card like the picture showing above, for now, all seem be well.
0001-sd-dts-config-sdmm3.patch.txt (1.1 KB)
