[gentoo-user] Re: Cohorent pool size too small...

[walt <w41ter@gmail.com>]

On 10/05/2014 06:52 AM, meino.cramer@gmx.de wrote:
> Hi,
> 
> while trying to get a mt7601sta (UWN200 WiFi dongle) driver running
> and working I came accross this in the dmesg output:
> 
> [    9.931938] usb 2-1: device v148f p7601 is not supported

This looks to me like it's the real error, not the one below.

> [    9.931976] usb 2-1: New USB device found, idVendor=148f, idProduct=7601
> [    9.931994] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> [   10.077532] rtusb init rt2870 --->
> [   10.079338] 
> 
> === pAd = e0c58000, size = 860808 ===
> 
> [   10.079939] ERROR: 256 KiB atomic DMA coherent pool is too small!
> Please increase it with coherent_pool= kernel parameter!
> [   10.079968] <-- ERROR in Alloc Bulk buffer for HTTxContext!
> [   10.079983] ---> RTMPFreeTxRxRingMemory
> [   10.080026] <--- RTMPFreeTxRxRingMemory
> [   10.080040] ERROR!!! Failed to allocate memory - TxRxRing
> 
> 
> But 
> 
> cat /proc/cmdline 
> 
> shows:
> 
> console=tty1 root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait fixrtc capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN,BB-BONE-EMMC-2G,coherent_pool=2M
> 
> (this is an embedded device, thats why there are the other parameters
> around...)
> 
> I do not find any way to set this parameter while compiling the
> kernel. And setting the kernel parameter seems not to work either...
> 
> Lost?
> 
> ...or am I only blind... ? ;)
> 
> How can I increase the cohorent pool size successfully?
> 
> Best regards,
> mcc
> 
> PS: The driver sources are not included in the kernel and have to be
> compiled externally/extra...
> 
> 
>