Re: [PATCH v12 6/9] usb: xhci: use bus->sysdev for DMA configuration

From: Jack Pham <jackp@codeaurora.org>
To: Peter Chen <peter.chen@nxp.com>
Cc: gregkh@linuxfoundation.org, stern@rowland.harvard.edu,
	ulf.hansson@linaro.org, broonie@kernel.org, sre@kernel.org,
	robh+dt@kernel.org, shawnguo@kernel.org, rjw@rjwysocki.net,
	dbaryshkov@gmail.com, heiko@sntech.de,
	linux-arm-kernel@lists.infradead.org, p.zabel@pengutronix.de,
	devicetree@vger.kernel.org, pawel.moll@arm.com,
	mark.rutland@arm.com, linux-usb@vger.kernel.org, arnd@arndb.de,
	s.hauer@pengutronix.de, mail@maciej.szmigiero.name,
	troy.kisky@boundarydevices.com, festevam@gmail.com,
	oscar@naiandei.net, stephen.boyd@linaro.org,
	linux-pm@vger.kernel.org, stillcompiling@gmail.com,
	linux-kernel@vger.kernel.org, mka@chromium.org,
	vaibhav.hiremath@linaro.org, gary.bisson@boundarydevices.com,
	hverkuil@xs4all.nl, krzk@kernel.org,
	Sriram Dash <sriram.dash@nxp.com>,
	Mathias Nyman <mathias.nyman@linux.intel.com>,
	Roger Quadros <rogerq@ti.com>
Subject: Re: [PATCH v12 6/9] usb: xhci: use bus->sysdev for DMA configuration
Date: Wed, 8 Feb 2017 12:43:00 -0800	[thread overview]
Message-ID: <20170208204300.GC8068@usblab-sd-06.qualcomm.com> (raw)
In-Reply-To: <1486372421-29073-7-git-send-email-peter.chen@nxp.com>

Hi Peter, Sriram, Arnd,

On Mon, Feb 06, 2017 at 05:13:38PM +0800, Peter Chen wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> For xhci-hcd platform device, all the DMA parameters are not
> configured properly, notably dma ops for dwc3 devices. So, set
> the dma for xhci from sysdev. sysdev is pointing to device that
> is known to the system firmware or hardware.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Sriram Dash <sriram.dash@nxp.com>
> Tested-by: Baolin Wang <baolin.wang@linaro.org>
> Tested-by: Vivek Gautam <vivek.gautam@codeaurora.org>
> Tested-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> ---
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 6d33b42..7a9c860 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c

> -	hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
> +	hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
> +			       dev_name(&pdev->dev), NULL);

As mentioned already in [1], usb_create_shared_hcd() is called to create
the second bus, however it also needs to be converted.

Not exactly as Roger's suggestion but this worked for me:

-       xhci->shared_hcd = usb_create_shared_hcd(driver, &pdev->dev,
+       xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
                        dev_name(&pdev->dev), hcd);
        if (!xhci->shared_hcd) {
                ret = -ENOMEM;

Without this, SuperSpeed devices fail to enumerate:

 usb 2-1: new SuperSpeed USB device number 2 using xhci-hcd
 usb 2-1: device descriptor read/8, error -11
 usb 2-1: new SuperSpeed USB device number 2 using xhci-hcd
 usb 2-1: device descriptor read/8, error -11
 usb 2-1: new SuperSpeed USB device number 3 using xhci-hcd
 usb 2-1: device descriptor read/8, error -11
 usb 2-1: new SuperSpeed USB device number 3 using xhci-hcd
 usb 2-1: device descriptor read/8, error -11
 <and continues...>

Thanks,
Jack

[1] https://lkml.org/lkml/2016/12/9/240
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