linux-kernel - Re: [PATCH v2, 2/3] usb: dwc3: core: add p3p2tranok quirk

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Message-ID: <20240604000147.2xxkkp7efjsbr3i5@synopsys.com>
Date: Tue, 4 Jun 2024 00:02:02 +0000
From: Thinh Nguyen <Thinh.Nguyen@...opsys.com>
To: joswang <joswang1221@...il.com>
CC: Thinh Nguyen <Thinh.Nguyen@...opsys.com>,
        "robh@...nel.org" <robh@...nel.org>,
        "krzk+dt@...nel.org" <krzk+dt@...nel.org>,
        "conor+dt@...nel.org" <conor+dt@...nel.org>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "balbi@...nel.org" <balbi@...nel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        joswang <joswang@...ovo.com>
Subject: Re: [PATCH v2, 2/3] usb: dwc3: core: add p3p2tranok quirk

On Mon, Jun 03, 2024, joswang wrote:
> From: joswang <joswang@...ovo.com>
> 
> In the case of enable hibernation, there is an issue with

I assume this is for host mode since we currently don't handle
hibernation in device mode (please confirm).

> the DWC31 2.00a and earlier versions where the controller
> link power state transition from P3/P3CPM/P4 to P2 may take
> longer than expected, ultimately resulting in the hibernation
> D3 entering time exceeding the expected 10ms.

Can you provide more context where the 10ms requirement is from?

> 
> Synopsys workaround:
> If the PHY supports direct P3 to P2 transition, program
> GUSB3PIPECTL.P3P2Tran0K=1.
> 

Which STAR issue is this?

> Therefore, adding p3p2tranok quirk for workaround hibernation
> D3 exceeded the expected entry time.
> 
> Signed-off-by: joswang <joswang@...ovo.com>
> ---

Please provide change note for v1->v2 here (and the rest of the other
patches).

>  drivers/usb/dwc3/core.c | 5 +++++
>  drivers/usb/dwc3/core.h | 4 ++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 7ee61a89520b..3a8fbc2d6b99 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -666,6 +666,9 @@ static int dwc3_ss_phy_setup(struct dwc3 *dwc, int index)
>  	if (dwc->dis_del_phy_power_chg_quirk)
>  		reg &= ~DWC3_GUSB3PIPECTL_DEPOCHANGE;
>  
> +	if (dwc->p2p3tranok_quirk)
> +		reg |= DWC3_GUSB3PIPECTL_P3P2TRANOK;
> +
>  	dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(index), reg);
>  
>  	return 0;
> @@ -1715,6 +1718,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
>  
>  	dwc->dis_split_quirk = device_property_read_bool(dev,
>  				"snps,dis-split-quirk");
> +	dwc->p2p3tranok_quirk = device_property_read_bool(dev,
> +				"snps,p2p3tranok-quirk");
>  
>  	dwc->lpm_nyet_threshold = lpm_nyet_threshold;
>  	dwc->tx_de_emphasis = tx_de_emphasis;
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 3781c736c1a1..2810dce8b42e 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -327,6 +327,7 @@
>  #define DWC3_GUSB3PIPECTL_DEP1P2P3_EN	DWC3_GUSB3PIPECTL_DEP1P2P3(1)
>  #define DWC3_GUSB3PIPECTL_DEPOCHANGE	BIT(18)
>  #define DWC3_GUSB3PIPECTL_SUSPHY	BIT(17)
> +#define DWC3_GUSB3PIPECTL_P3P2TRANOK	BIT(11)
>  #define DWC3_GUSB3PIPECTL_LFPSFILT	BIT(9)
>  #define DWC3_GUSB3PIPECTL_RX_DETOPOLL	BIT(8)
>  #define DWC3_GUSB3PIPECTL_TX_DEEPH_MASK	DWC3_GUSB3PIPECTL_TX_DEEPH(3)
> @@ -1132,6 +1133,8 @@ struct dwc3_scratchpad_array {
>   *			instances in park mode.
>   * @parkmode_disable_hs_quirk: set if we need to disable all HishSpeed
>   *			instances in park mode.
> + * @p2p3tranok_quirk: set if Controller transitions directly from phy
> + *			power state P2 to P3 or from state P3 to P2.
>   * @gfladj_refclk_lpm_sel: set if we need to enable SOF/ITP counter
>   *                          running based on ref_clk
>   * @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
> @@ -1361,6 +1364,7 @@ struct dwc3 {
>  	unsigned		ulpi_ext_vbus_drv:1;
>  	unsigned		parkmode_disable_ss_quirk:1;
>  	unsigned		parkmode_disable_hs_quirk:1;
> +	unsigned		p2p3tranok_quirk:1;
>  	unsigned		gfladj_refclk_lpm_sel:1;
>  
>  	unsigned		tx_de_emphasis_quirk:1;
> -- 
> 2.17.1
> 

Thanks,
Thinh