FYI: What a fairly-modern linux's /sys/kernel/debug/mmc0/ios reports on a Pine64+ 2GB for a Sandisk Ultra 128GB Micro SDXC UHS-I Card from a SDSQUAR-128G-GN6MA
Mark Millard
marklmi at yahoo.com
Tue Sep 4 01:43:16 UTC 2018
[The Pine64+ 2GB focus is just because that is all I
currently have access to for aarch64. I have no access
to armv7 or such currently. The amd64 context is via
virtualbox under macOS and so not relevant.]
I finally have access to similar capacity microsdxc media
to the previous e.MMC-on-adapter media that I had been
using with the Pine64+ 2GB. The card tested for this
is from a:
Sandisk Ultra 128GB Micro SDXC UHS-I Card with Adapter SDSQUAR-128G-GN6MA
So I dd'd the fairly linux that I tested the e.MMC with
over to the microsdxc. The linux is from:
https://dl.armbian.com/pine64/Ubuntu_bionic_dev_nightly.7z
which is:
nightly mainline kernel master branch 4.17.y or 4.18.y
It shows as:
# uname -ap
Linux pine64 4.18.0-rc4-sunxi64 #220 SMP Sun Jul 15 14:16:31 UTC 2018 aarch64 aarch64 aarch64 GNU/Linux
For the sdcard from the SDSQXBG-128G-GN6MA:
# cat /sys/kernel/debug/mmc0/ios
clock: 50000000 Hz
actual clock: 50000000 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: 2 (sd high-speed)
signal voltage: 0 (3.30 V)
driver type: 0 (driver type B)
# hdparm -t /dev/mmcblk0
/dev/mmcblk0:
Timing buffered disk reads: 70 MB in 3.07 seconds = 22.80 MB/sec
(As I gather: all as expected.)
For reference the e.MMC on an adapter used in the
Pine64+ 2GB for this linux had shown:
# cat /sys/kernel/debug/mmc0/ios
clock: 52000000 Hz
actual clock: 50000000 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: 8 (mmc DDR52)
signal voltage: 0 (3.30 V)
driver type: 0 (driver type B)
# hdparm -t /dev/mmcblk0
/dev/mmcblk0:
Timing buffered disk reads: 134 MB in 3.04 seconds = 44.03 MB/sec
(As I gather: this was surprising.)
===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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