Recommended value for coherent_pool parameter ?

[dhead666]

After updating my PogoPlug 4 system I'm getting an error about coherent_pool size when the system try to load a firmware of dvb-t usb device.

linux-kirkwood & linux-headers-kirkwood: updated from 3.9.6-1 to 3.11.1-2
linux-firmware: updated from 20130610-1 to 20130917-1

I guess I'll need to set this manually in the uboot, any recommended value for the size of coherent_pool ?

$this->bbcode_second_pass_code('', '
[ 21.706890] it913x: Chip Version=01 Chip Type=9135
[ 21.708431] it913x: Remote HID mode NOT SUPPORTED
[ 21.708860] it913x: Dual mode=0 Tuner Type=0
[ 21.710375] usb 2-1: dvb_usb_v2: found a 'ITE 9135(9006) Generic' in cold state
[ 21.717766] usb 2-1: dvb_usb_v2: downloading firmware from file 'dvb-usb-it9135-01.fw'
[ 21.728792] usbcore: registered new interface driver dvb_usb_it913x
[ 21.912265] usbcore: registered new interface driver usbhid
[ 21.912287] usbhid: USB HID core driver
[ 22.045207] input: ITE Technologies, Inc. DVB-T TV Stick as /devices/pci0000:00/0000:00:01.0/usb2/2-1/2-1:1.1/input/input1
[ 22.046987] hid-generic 0003:048D:9006.0001: input: USB HID v1.01 Keyboard [ITE Technologies, Inc. DVB-T TV Stick] on usb-0000:00:01.0-1/input1
[ 21.718154] it913x: FRM Starting Firmware Download
[ 22.397810] it913x: FRM Firmware Download Completed - Resetting Device
[ 22.432083] it913x: Chip Version=01 Chip Type=9135
[ 22.432455] it913x: Firmware Version 204869120
[ 22.463458] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
[ 22.511648] usb 2-1: dvb_usb_v2: found a 'ITE 9135(9006) Generic' in warm state
[ 22.511897] usb 2-1: dvb_usb_v2: will pass the complete MPEG2 transport stream to the software demuxer
[ 22.512517] ERROR: 256 KiB atomic DMA coherent pool is too small!
Please increase it with coherent_pool= kernel parameter!
[ 22.561518] usb 2-1: dvb_usb_v2: 'ITE 9135(9006) Generic' error while loading driver (-12)
[ 22.563007] usb 2-1: dvb_usb_v2: 'ITE 9135(9006) Generic' successfully deinitialized and disconnected
')

[dhead666]

1M seems to do the trick.

Changing the uboot param value from Arch Linux "bricked" my device and I had to take out the soldering iron to use serial connection (did't set the netconsole on uboot) and set again my uboot params.

The steps I've took to change the param from uboot that ended in bricked device:
$this->bbcode_second_pass_code('', '# pacman -Syy uboot-env mtd-utils
# nano /etc/fw_env.config')
Enabled the iomega iconnect configs and printed the current environment parms (/dev/mtd0 0xa0000 0x20000 0x20000)
$this->bbcode_second_pass_code('', 'fw_printenv')
Updated the param
$this->bbcode_second_pass_code('', 'fw_setenv alarm_args 'setenv bootargs console=ttyS0,115200 root=$device rootwait rootfstype=ext3 coherent_pool=1M'')

As I opened the post restoring the params by serial serial connection unbricked the device and I kept the value "coherent_pool=1M" which fixed the issue with the driver firmware of the dvb usb device.

[moonman]

With Series 4 you need to use blparm

[dhead666]

Thank moonman.

For anyone that stumble upon this thread the package is "pogoplug-blparam" and I advise you to not execute "blparam --help" (google it to find why).