Re: [PATCH v2] usb: host: xhci-plat: fix support for XHCI_SKIP_PHY_INIT quirk

From: Peter Chen <peter.chen@nxp.com>
To: "Pali Rohár" <pali@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jun Li <jun.li@nxp.com>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] usb: host: xhci-plat: fix support for XHCI_SKIP_PHY_INIT quirk
Date: Thu, 24 Dec 2020 05:59:05 +0000	[thread overview]
Message-ID: <20201224055836.GB27629@b29397-desktop> (raw)
In-Reply-To: <20201223161847.10811-1-pali@kernel.org>

On 20-12-23 17:18:47, Pali Rohár wrote:
> Currently init_quirk callbacks for xhci platform drivers are called
> xhci_plat_setup() function which is called after chip reset completes.
> It happens in the middle of the usb_add_hcd() function.
> 
> But XHCI_SKIP_PHY_INIT quirk is checked in the xhci_plat_probe() function
> prior calling usb_add_hcd() function. Therefore this XHCI_SKIP_PHY_INIT
> currently does nothing as prior xhci_plat_setup() it is not set.
> 
> Quirk XHCI_SKIP_PHY_INIT is only setting hcd->skip_phy_initialization value
> which really needs to be set prior calling usb_add_hcd() as this function
> at its beginning skips PHY init if this member is set.
> 
> This patch fixes implementation of the XHCI_SKIP_PHY_INIT quirk by calling
> init_quirk callbacks (via xhci_priv_init_quirk()) prior checking if
> XHCI_SKIP_PHY_INIT is set. Also checking if either xhci->quirks or
> priv->quirks contains this XHCI_SKIP_PHY_INIT quirk.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> 
> ---
> Changes in v2:
> * Check also xhci->quirks as xhci_priv_init_quirk() callbacks are setting xhci->quirks
> * Tested with "usb: host: xhci: mvebu: make USB 3.0 PHY optional for Armada 3720" patch
> * Removed Fixes: line
> ---
>  drivers/usb/host/xhci-plat.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 4d34f6005381..0eab7cb5a767 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -89,13 +89,6 @@ static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
>  /* called during probe() after chip reset completes */
>  static int xhci_plat_setup(struct usb_hcd *hcd)
>  {
> -	int ret;
> -
> -
> -	ret = xhci_priv_init_quirk(hcd);
> -	if (ret)
> -		return ret;
> -
>  	return xhci_gen_setup(hcd, xhci_plat_quirks);
>  }
>  
> @@ -330,7 +323,14 @@ static int xhci_plat_probe(struct platform_device *pdev)
>  
>  	hcd->tpl_support = of_usb_host_tpl_support(sysdev->of_node);
>  	xhci->shared_hcd->tpl_support = hcd->tpl_support;
> -	if (priv && (priv->quirks & XHCI_SKIP_PHY_INIT))
> +
> +	if (priv) {
> +		ret = xhci_priv_init_quirk(hcd);
> +		if (ret)
> +			goto disable_usb_phy;
> +	}
> +
> +	if ((xhci->quirks & XHCI_SKIP_PHY_INIT) || (priv && (priv->quirks & XHCI_SKIP_PHY_INIT)))
>  		hcd->skip_phy_initialization = 1;

I am not sure if others agree with you move the position of
xhci_priv_init_quirk, Let's see Mathias opinion.

-- 

Thanks,
Peter Chen