One thing I am not sure of is if there are things we can do in the driver to improve things based on the Micron controller. One idea is that as we know the controller and are not subject to heaven only knows what controller is in the SD card a person buys. They are all over the map.
On Thu, 31 Jan 2013 14:42:28 -0500
Andrew Bradford <andrew@bradfordembedded.com> wrote:
<snip>
Now in 8 bit mode:
> root@beaglebone:~/flashbench# cat /sys/kernel/debug/mmc1/*
> 2>/dev/null | grep -v ^$ 52000000
> clock: 52000000 Hz
> vdd: 7 (1.65 - 1.95 V)
> bus mode: 2 (push-pull)
> chip select: 0 (don't care)
> power mode: 2 (on)
> bus width: 2 (4 bits)
> timing spec: 1 (mmc high-speed)
> signal voltage: 0 (3.30 V)
> mmc1:
> ctx_loss: 0:0
> regs:
> CON: 0x00000600
> HCTL: 0x00000b06
> SYSCTL: 0x000c0087
> IE: 0x00000000
> ISE: 0x00000000
> CAPA: 0x06e10080
root@beaglebone:~# cat /sys/kernel/debug/mmc1/* 2>/dev/null | grep -v ^$
52000000bus width: 3 (8 bits)
clock: 52000000 Hz
vdd: 7 (1.65 - 1.95 V)
bus mode: 2 (push-pull)
chip select: 0 (don't care)
power mode: 2 (on)
timing spec: 1 (mmc high-speed)CON: 0x00000620
signal voltage: 0 (3.30 V)
mmc1:
ctx_loss: 0:0
regs:
HCTL: 0x00000b04
SYSCTL: 0x000c0087root@beaglebone:~# dd if=/dev/zero of=/dev/mmcblk1 bs=1M count=256 oflag=direct
IE: 0x00000000
ISE: 0x00000000
CAPA: 0x06e10080
> root@beaglebone:~/flashbench# dd if=/dev/zero of=/dev/mmcblk1 bs=1M
> count=256 oflag=direct 256+0 records in
> 256+0 records out
> 268435456 bytes (268 MB) copied, 46.5893 s, 5.8 MB/s
>
> root@beaglebone:~/flashbench# dd if=/dev/mmcblk1 of=/dev/null bs=1M
> count=256 iflag=direct 256+0 records in
> 256+0 records out
> 268435456 bytes (268 MB) copied, 15.1334 s, 17.7 MB/s
256+0 records in268435456 bytes (268 MB) copied, 47.8116 s, 5.6 MB/s
256+0 records out
root@beaglebone:~# dd if=/dev/mmcblk1 of=/dev/null bs=1M count=256 iflag=direct
256+0 records in268435456 bytes (268 MB) copied, 11.9116 s, 22.5 MB/s
256+0 records out
## Not quite the speeds listed in the Micron data sheet.
## Is better than 4 bit mode, though.
<snip>
In 8 bit mode, open-au tests look the same as 4 bit mode, which should be
expected as the controller is the bottleneck on writes anyway.
-Andrew
--
You received this message because you are subscribed to the Google Groups "Beagle Alpha" group.
To unsubscribe from this group and stop receiving emails from it, send an email to beagle-alpha+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.