On 8/31/2016 2:38 AM, Felipe Balbi wrote:
> If we don't know what are the actual U1/U2 exit
> latencies from the UDC, we're better off using
> maximum latencies as default. This should avoid
> any problems with too frequent U1/U2 entry.
>
> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
> ---
> include/linux/usb/gadget.h | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 3667d667cab1..20cb590c658e 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -276,11 +276,19 @@ static inline void usb_ep_fifo_flush(struct usb_ep *ep)
>
> /*-------------------------------------------------------------------------*/
>
> +/**
> + * struct usb_dcd_config_params - Default U1/U2 exit latencies
> + * @bU1DevExitLat: U1 Exit Latency in us
> + * @bU2DevExitLat: U2 Exit Latency in us
> + *
> + * Note that we will be setting U1/U2 exit latencies to their maximum
> + * by default if no value is passed by the UDC Driver.
> + */
> struct usb_dcd_config_params {
> __u8 bU1DevExitLat; /* U1 Device exit Latency */
> -#define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */
> +#define USB_DEFAULT_U1_DEV_EXIT_LAT 10 /* us */
> __le16 wU2DevExitLat; /* U2 Device exit Latency */
> -#define USB_DEFAULT_U2_DEV_EXIT_LAT 0x1F4 /* Less then 500 microsec */
> +#define USB_DEFAULT_U2_DEV_EXIT_LAT 2047 /* us */
> };
>
>
>
Hi Felipe,
Speaking of this, how would you feel about adding module parameters in
the dwc3-pci to set these? And we also have several more settings in
our internal tree that we need for IP validation and debugging.
As you know the IP is highly configurable, and we do much of the
testing against these configurations via software settings. And our
validation platform is not a typical platform. Basically we have a
single platform, but the instantiated IP and PHY could be configured
in any way so it could need different values passed in for
testing. Like the U1/U2 exit latencies, LPM NYET threshold, HIRD,
USB2/3 SUSPHY, LPM sleep mode, GFLADJ, etc.
And some things that are automatically detected we need to restrict or
disable to get full coverage. Such as disabling U1/U2 and LPM, maximum
speed, dr_mode, NUMP, RX thresholding, RX thresholding packet count.
I know module parameters are typically frowned upon so do you
recommend another approach?
Regards,
John
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