linux-kernel - Re: [PATCH] usb: host: xhci-plat: Iterate over parent nodes for finding quirks

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Message-ID: <b819a5fc-82aa-dc9c-4272-fecdacbd5880@intel.com>
Date:   Fri, 20 Jul 2018 17:42:30 +0300
From:   Mathias Nyman <mathias.nyman@...el.com>
To:     Anurag Kumar Vulisha <anurag.kumar.vulisha@...inx.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] usb: host: xhci-plat: Iterate over parent nodes for
 finding quirks

Hi

Sorry about the delay with this patch,
I have a couple comments inline.

On 05.06.2018 18:20, Anurag Kumar Vulisha wrote:
> In xhci_plat_probe() both sysdev and pdev->dev are being used
> for finding quirks. There are some drivers(like dwc3 host.c)
> which adds quirks(like usb3-lpm-capable) into pdev and the logic
> present in xhci_plat_probe() checks for quirks in either sysdev
> or pdev for finding the quirks. Because of this logic, some of
> the quirks are getting missed(usb3-lpm-capable quirk added by dwc3
> host.c driver is getting missed).This patch fixes this by iterating
> over all the available parents for finding the quirks. In this way
> all the quirks which are present in child or parent are correctly
> updated.
> 
> Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@...inx.com>
> ---
>   drivers/usb/host/xhci-plat.c | 29 ++++++++++++++++++-----------
>   1 file changed, 18 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index c1b22fc..0cd0489 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -152,7 +152,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
>   {
>   	const struct xhci_plat_priv *priv_match;
>   	const struct hc_driver	*driver;
> -	struct device		*sysdev;
> +	struct device		*sysdev, *tmpdev;
>   	struct xhci_hcd		*xhci;
>   	struct resource         *res;
>   	struct usb_hcd		*hcd;
> @@ -272,19 +272,26 @@ static int xhci_plat_probe(struct platform_device *pdev)
>   		goto disable_clk;
>   	}
>   
> -	if (device_property_read_bool(sysdev, "usb2-lpm-disable"))
> -		xhci->quirks |= XHCI_HW_LPM_DISABLE;
> +	/* Iterate over all parent nodes for finding quirks */
> +	for (tmpdev = &pdev->dev; tmpdev; tmpdev = tmpdev->parent) {

Isn't sysdev at this point the topmost device that can have any of those
device properties set?
We could loop from &pdev->dev up to and including sysdev.

It doesn't matter much but maybe avoid walking some extra parents.
   
>   
> -	if (device_property_read_bool(sysdev, "usb3-lpm-capable"))
> -		xhci->quirks |= XHCI_LPM_SUPPORT;
> +		if (device_property_read_bool(tmpdev, "usb2-lpm-disable"))
> +			xhci->quirks |= XHCI_HW_LPM_DISABLE;
>   
> -	if (device_property_read_bool(&pdev->dev, "quirk-broken-port-ped"))
> -		xhci->quirks |= XHCI_BROKEN_PORT_PED;
> +		if (device_property_read_bool(tmpdev, "usb3-lpm-capable"))
> +			xhci->quirks |= XHCI_LPM_SUPPORT;
>   
> -	/* imod_interval is the interrupt moderation value in nanoseconds. */
> -	xhci->imod_interval = 40000;

Setting the default imod_interval could be moved before the for() loop

> -	device_property_read_u32(sysdev, "imod-interval-ns",
> -				 &xhci->imod_interval);
> +		if (device_property_read_bool(tmpdev, "quirk-broken-port-ped"))
> +			xhci->quirks |= XHCI_BROKEN_PORT_PED;
> +
> +		/*
> +		 * imod_interval is the interrupt moderation
> +		 * value in nanoseconds.
> +		 */
> +		xhci->imod_interval = 40000;
> +		device_property_read_u32(tmpdev, "imod-interval-ns",
> +					 &xhci->imod_interval);
> +	}
>   
>   	hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev, "usb-phy", 0);
>   	if (IS_ERR(hcd->usb_phy)) {
> 

Otherwise everything looks fine.
I will unfortunately be away again for another two weeks.

-Mathias