[PATCH V2 RFC 1/6] usb: dwc2: core: Avoid nonsense error in gadget mode

[Stefan Wahren]

Hi John,

> John Youn <John.Youn at synopsys.com> hat am 16. August 2016 um 21:20
> geschrieben:
> 
> 
> On 8/16/2016 9:44 AM, Stefan Wahren wrote:
> > Hi John,
> > 
> >> John Youn <John.Youn at synopsys.com> hat am 16. August 2016 um 03:30
> ...
> > [    2.476378] dwc2 20980000.usb: dwc2_set_parameters()
> > [    2.476391] dwc2 20980000.usb: Setting dma_desc_fs_enable to 0
> > [    2.476418] dwc2 20980000.usb: Setting external_id_pin_ctl to 0
> > [    2.476429] dwc2 20980000.usb: Setting hibernation to 0
> > [    2.476449] dwc2 20980000.usb: 0 invalid for host_rx_fifo_size. Check HW
> > configuration.
> > [    2.491704] dwc2 20980000.usb: Setting host_rx_fifo_size to 4096
> > [    2.491727] dwc2 20980000.usb: 0 invalid for host_nperio_tx_fifo_size.
> > Check
> > HW configuration.
> > [    2.507853] dwc2 20980000.usb: Setting host_nperio_tx_fifo_size to 0
> > [    2.507875] dwc2 20980000.usb: 0 invalid for host_perio_tx_fifo_size.
> > Check
> > HW configuration.
> > [    2.524246] dwc2 20980000.usb: Setting host_perio_tx_fifo_size to 0
> 
> Thanks for the logs.
> 
> It looks like if dr_mode == peripheral, dwc2 doesn't populate the
> following host-only values from the reset values of the registers.
> 
> * hw_params->host_nperio_tx_fifo_size
> * hw_params->host_perio_tx_fifo_size
> 
> Thus when it goes to set the core_params based on the hw_params you
> get the error. As peripheral-only, they are never used so it's fine.
> 
> To get rid of the error we can skip setting the host-only parameters
> if dr_mode == peripheral.

sorry the subject is imprecise. According to the logs if dr_mode == otg we also
get

[    2.569573] dwc2 20980000.usb: 0 invalid for host_perio_tx_fifo_size. Check
HW configuration.
[    2.585354] dwc2 20980000.usb: Setting host_perio_tx_fifo_size to 0

You already said in 6/6 that's faulty, but i only want to point it out.

Stefan