[3/3] usb: dwc3: Support option to disable USB2 LPM

[Roger Quadros <rogerq@ti.com>]

Hi,

On 08/11/18 04:10, Thinh Nguyen wrote:
> Support the option to disable USB2 LPM. Set xhci "usb2-lpm-disable"
> property via "snps,usb2-lpm-disable" property.
> 
> Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
> ---
>  drivers/usb/dwc3/core.c | 2 ++
>  drivers/usb/dwc3/core.h | 2 ++
>  drivers/usb/dwc3/host.c | 5 ++++-
>  3 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index a4068a7b95dd..f6b80a545a78 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1248,6 +1248,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
>  				&hird_threshold);
>  	dwc->usb3_lpm_capable = device_property_read_bool(dev,
>  				"snps,usb3_lpm_capable");
> +	dwc->usb2_lpm_disable = device_property_read_bool(dev,
> +				"snps,usb2-lpm-disable");

Can we use the same logic as usb3_lpm instead?
i.e. enable USB2 LPM only if "snps,usb2_lpm_capable" is present in DT.
This is because older platforms that are not tested for usb2 lpm
might break if you enable it by default.

Also can we have some consistency in usage of '-' vs '_'?

>  	device_property_read_u8(dev, "snps,rx-thr-num-pkt-prd",
>  				&rx_thr_num_pkt_prd);
>  	device_property_read_u8(dev, "snps,rx-max-burst-prd",
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 5bfb62533e0f..ca7b5f46e1f0 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -971,6 +971,7 @@ struct dwc3_scratchpad_array {
>   * @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
>   * @three_stage_setup: set if we perform a three phase setup
>   * @usb3_lpm_capable: set if hadrware supports Link Power Management
> + * @usb2_lpm_disable: set to disable usb2 lpm
>   * @disable_scramble_quirk: set if we enable the disable scramble quirk
>   * @u2exit_lfps_quirk: set if we enable u2exit lfps quirk
>   * @u2ss_inp3_quirk: set if we enable P3 OK for U2/SS Inactive quirk
> @@ -1146,6 +1147,7 @@ struct dwc3 {
>  	unsigned		setup_packet_pending:1;
>  	unsigned		three_stage_setup:1;
>  	unsigned		usb3_lpm_capable:1;
> +	unsigned		usb2_lpm_disable:1;
>  
>  	unsigned		disable_scramble_quirk:1;
>  	unsigned		u2exit_lfps_quirk:1;
> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> index 1a3878a3be78..f55947294f7c 100644
> --- a/drivers/usb/dwc3/host.c
> +++ b/drivers/usb/dwc3/host.c
> @@ -46,7 +46,7 @@ static int dwc3_host_get_irq(struct dwc3 *dwc)
>  
>  int dwc3_host_init(struct dwc3 *dwc)
>  {
> -	struct property_entry	props[3];
> +	struct property_entry	props[4];
>  	struct platform_device	*xhci;
>  	int			ret, irq;
>  	struct resource		*res;
> @@ -93,6 +93,9 @@ int dwc3_host_init(struct dwc3 *dwc)
>  	if (dwc->usb3_lpm_capable)
>  		props[prop_idx++].name = "usb3-lpm-capable";
>  
> +	if (dwc->usb2_lpm_disable)
> +		props[prop_idx++].name = "usb2-lpm-disable";
> +
>  	/**
>  	 * WORKAROUND: dwc3 revisions <=3.00a have a limitation
>  	 * where Port Disable command doesn't work.
> 

cheers,
-roger