Hi Maxime

> So you're using a DT for a board that is not yours. Please NEVER do
> that, unless you're willing to take the risk of blowing your board up.
I'm using the "A13-SOM" cpu module from Olimex ....which I believed was a
close match to the "A13-OLinuXino" board minus some peripherals. I'm using
them to learn so have a half dozen for when they break. ..."touch wood" so
far so good.


> Do you have pullups on that bus?
Nothing is connected to the module besides the 3.3V power and a uart for
uart0 (console)  ...it's booting from sdcard. Previously I was using the
A20-SOM ....although that was via the EVB. Would a Soc require pullups to
scan an empty bus?  ...perhaps this is my problem.

As always thanks again for your help!


Bruce



On Fri, Jun 19, 2015 at 8:10 AM, Maxime Ripard <
[email protected]> wrote:

> Hi,
>
> On Thu, Jun 18, 2015 at 10:46:41PM +0100, bruce bushby wrote:
> > Hi
> >
> > I wanted to ask if anybody is having or has had problems with "A13 I2C
> bus
> > locked"?
> >
> > I'm using a "Latest" version of u-boot and 4.1 release candidate. I've
> also
> > tried using an older U-Boot (2014.04) .... tomorrow I'll try some older
> > kernels but thought I would check with the list at the same time.
> >
> > I'm using the Olimex A13-SOM with nothing connected and have tried a
> couple
> > of different power supplies just in case it was a voltage issue.
> >
> >
> >
> > Some console extracts:
> >
> >
> > U-Boot SPL 2015.04 (Jun 18 2015 - 17:32:42)
> > DRAM: 512 MiB
> > Failed to set core voltage! Can't set CPU frequency
> >
> >
> > U-Boot 2015.04 (Jun 18 2015 - 17:32:42) Allwinner Technology
> >
> > CPU:   Allwinner A13 (SUN5I)
> > I2C:   ready
> > DRAM:  512 MiB
> > MMC:   SUNXI SD/MMC: 0
> > *** Warning - bad CRC, using default environment
> >
> > Setting up a 1024x768 vga console
> > In:    serial
> > Out:   vga
> > Err:   vga
> > Net:   No ethernet found.
> > starting USB...
> > USB0:   USB EHCI 1.00
> > scanning bus 0 for devices... 1 USB Device(s) found
> >        scanning usb for storage devices... 0 Storage Device(s) found
> > Hit any key to stop autoboot:  0
> > switch to partitions #0, OK
> > mmc0 is current device
> > Scanning mmc 0:1...
> > Found U-Boot script /boot.scr
> > reading /boot.scr
> > 318 bytes read in 21 ms (14.6 KiB/s)
> > ## Executing script at 43100000
> > reading uImage
> > 4281912 bytes read in 666 ms (6.1 MiB/s)
> > reading sun5i-a13-olinuxino-micro.dtb
>
> So you're using a DT for a board that is not yours. Please NEVER do
> that, unless you're willing to take the risk of blowing your board up.
>
> > 14674 bytes read in 36 ms (397.5 KiB/s)
> > ## Booting kernel from Legacy Image at 46000000 ...
> >    Image Name:   Linux-4.1.0-rc6
> >    Image Type:   ARM Linux Kernel Image (uncompressed)
> >    Data Size:    4281848 Bytes = 4.1 MiB
> >    Load Address: 40008000
> >    Entry Point:  40008000
> >    Verifying Checksum ... OK
> > ## Flattened Device Tree blob at 49000000
> >    Booting using the fdt blob at 0x49000000
> >    Loading Kernel Image ... OK
> >    Using Device Tree in place at 49000000, end 49006951
> >
> > Starting kernel ...
> >
> > [    0.000000] Booting Linux on physical CPU 0x0
> > [    0.000000] Initializing cgroup subsys cpuset
> > [    0.000000] Initializing cgroup subsys cpu
> > [    0.000000] Initializing cgroup subsys cpuacct
> > [    0.000000] Linux version 4.1.0-rc6 ([email protected]) (gcc
> version
> > 4.9.2 (Buildroot 2015.08-git-00187-g0db1c13) ) #1 SMP Thu Jun 18 17:40:32
> > BST 2015
> >
> > ......
>
> Usually these dots are helpful.
>
>
> > # ls -l /dev | grep i2c
> > crw-------    1 root     root       89,   0 Jan  1 00:00 i2c-0
> > crw-------    1 root     root       89,   1 Jan  1 00:00 i2c-1
> > crw-------    1 root     root       89,   2 Jan  1 00:00 i2c-2
> > #
> > # i2cdetect -l
> > i2c-0   i2c             mv64xxx_i2c adapter                     I2C
> adapter
> > i2c-1   i2c             mv64xxx_i2c adapter                     I2C
> adapter
> > i2c-2   i2c             mv64xxx_i2c adapter                     I2C
> adapter
> > #
> > # i2cdetect -y 0
> >      0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
> > 00:          [   55.294387] i2c i2c-0: mv64xxx: I2C bus locked, block: 1,
> > time_left: 0
> > -- [   57.294387] i2c i2c-0: mv64xxx: , block: 1, time_left: 0
> > -- [   59.294474] i2c i2c-0: mv64xxx: I2C bus locked, block: 1,
> time_left: 0
> > -- [   61.294381] i2c i2c-0: mv64xxx: I2C bus locked, block: 1,
> time_left: 0
> > -- ^C[   63.294436] i2c i2c-0: mv64xxx: I2C bus locked, block: 1,
> > time_left: 0
>
> Do you have pullups on that bus?
>
> Maxime
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com
>

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