High CPU load produced by USB (DW2)

Mirza Krak mirza.krak at gmail.com
Thu Feb 8 05:06:58 PST 2018

On 8 February 2018 at 12:02, Minas Harutyunyan
<Minas.Harutyunyan at synopsys.com> wrote:
> Hi Mirza,
> On 2/7/2018 1:49 PM, Mirza Krak wrote:

< snip >

> Could you please provide additional info:
> 1. Does your core support descriptor DMA mode? (bits 31 and 30 of GHWCFG4).
> 2. Version of core (GSNPSID)?

It does seem to support descriptor DMA mode, and content of both
GHWCFG4 and GSNPSID are posted below.

root at esp5-d1:~# dmesg | grep -E "GHWCFG4|GSNPSID"
[    1.109298] dwc2 ff540000.usb: GSNPSID @0xF0940040 : 0x4F54310A
[    1.109344] dwc2 ff540000.usb: GHWCFG4 @0xF0940050 : 0xC8004030
[    1.489016] dwc2 ff580000.usb: GSNPSID @0xF09C0040 : 0x4F54310A
[    1.489063] dwc2 ff580000.usb: GHWCFG4 @0xF09C0050 : 0xDBF04030

Full register dump at boot (no devices connected) can be found at [1].

> 3. Do you connect any HS HUB between dwc core port and keyboard? Is it
> available connection scenarios when Split traffic generated?

There is actually an HS HUB (FE1_QFP48) between dwc core and keyboard,
I was not aware of it but it is mounted on the board.

[1]. https://gist.github.com/mirzak/a6245dddd4670f3b908a9783f9db8b0d
Med Vänliga Hälsningar / Best Regards

Mirza Krak

More information about the Linux-rockchip mailing list