SD Memory Card's Remount Problem....!

Hi! I’m developing with L4T 28.1 version on TX1 Jetson Reference Board.
There is an strange phenomenon about SD Memory Card.
When SD Memory Card is inserted after unmounted and removed, it isn’t often detected and remounted atomatically.
But in that case all is done successfully when it is inserted after removing again and waiting for about one minute.
In my short opinion, there is deliberate delay time on SDHC driver to prevent repeated phenomenon failing automatic card detection.
If it is true, how much Can I reduce the delay time ?

I could be wrong, but I doubt there would be an intentional delay time of that magnitude. More likely something is timing out. You may want to monitor logs while doing all insert/remove operations via:

dmesg --follow

See what logs show.

It may also be of interest as to what file system type and partitioning exists on the SD card. Assuming this is “/dev/mmcblk1” try:

sudo gdisk -l /dev/mmcblk1

Also, while the card is plugged in:

lsblk -f /dev/mmcblk1

Tanks for linuxdev’s reply.
When SD Card can’t be mounted, following kernel message is printed.
Why does this error happen frequently ?

[50504.408334] mmc2: error -110 whilst initialising SD card
[50504.563938] mmc2: error -110 whilst initialising SD card
[50504.700077] mmc2: error -110 whilst initialising SD card
[50504.767344] mmc2: sdhci_cmd_irq 2634 SDHCI_INT_CRC intmask: a0000 Interface clock = 6000000Hz
[50504.775912] sdhci: =========== REGISTER DUMP (mmc2)===========
[50504.781766] sdhci: Sys addr: 0x00000000 | Version: 0x00000303
[50504.787617] sdhci: Blk size: 0x00000000 | Blk cnt: 0x00000000
[50504.793465] sdhci: Argument: 0x00000000 | Trn mode: 0x00000000
[50504.799312] sdhci: Present: 0x01fb0000 | Host ctl: 0x00000000
[50504.805160] sdhci: Power: 0x00000001 | Blk gap: 0x00000000
[50504.811007] sdhci: Wake-up: 0x00000000 | Clock: 0x00001e07
[50504.816850] sdhci: Timeout: 0x00000000 | Int stat: 0x00000001
[50504.822697] sdhci: Int enab: 0x00ff0003 | Sig enab: 0x00fc0003
[50504.828540] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
[50504.834385] sdhci: Caps: 0x376cd08c | Caps_1: 0x10006f73
[50504.840229] sdhci: Cmd: 0x0000371a | Max curr: 0x00000000
[50504.846072] sdhci: Host ctl2: 0x00003000
[50504.850013] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x0000000080000010
[50504.856546] sdhci: ===========================================

Someone else will have to comment on possible causes, but it seems to be a hardware issue (notice the checksum error). The issue could be with the SD card itself, or just marginal signal quality. The delay you see is not intentional, but is instead a side-effect of something in initializing failing and having to try again. Do you have other SD cards you can check?