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From: Felipe Balbi <balbi@ti.com>
To: Apelete Seketeli <apelete@seketeli.net>
Cc: <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	Felipe Balbi <balbi@ti.com>, Lars-Peter Clausen <lars@metafoo.de>
Subject: Re: [PATCH 3/3] usb: musb: fix setting JZ4740 gadget periphal mode on reset
Date: Mon, 16 Dec 2013 15:20:56 -0600	[thread overview]
Message-ID: <20131216212056.GE12896@saruman.home> (raw)
In-Reply-To: <1386992918-1531-4-git-send-email-apelete@seketeli.net>

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On Sat, Dec 14, 2013 at 04:48:38AM +0100, Apelete Seketeli wrote:
> JZ4740 USB Device Controller is not OTG compatible and does not have DEVCTL
> register in silicon.
> 
> During ethernet-over-usb transactions, on reset, musb driver tries to
> read from DEVCTL and consequently sets device as host (A-Device)
> instead of peripheral (B-Device), which makes it a composite device to
> the USB gadget driver.
> This induces a kernel panic during power down where the USB gadget
> driver does a null pointer dereference when trying to access the
> composite device configuration.
> 
> On reset, do not rely on DEVCTL value for setting gadget peripheral
> mode: hardcode it instead to B-Device.
> 
> Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
> ---
>  drivers/usb/musb/musb_gadget.c |    9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
> index 32fb057..b4bea7a 100644
> --- a/drivers/usb/musb/musb_gadget.c
> +++ b/drivers/usb/musb/musb_gadget.c
> @@ -2119,6 +2119,14 @@ __acquires(musb->lock)
>  	/* Normal reset, as B-Device;
>  	 * or else after HNP, as A-Device
>  	 */
> +#if defined(CONFIG_USB_MUSB_JZ4740) || defined(CONFIG_USB_MUSB_JZ4740_MODULE)

NAK, no ifdefs in this driver. Pass a quirk flag through platform_data
or something similar.

-- 
balbi

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  reply	other threads:[~2013-12-16 21:21 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-14  3:48 [PATCH 0/3] Add USB support for Ingenic JZ4740 Apelete Seketeli
2013-12-14  3:48 ` [PATCH 1/3] mips: qi_lb60: add defconfig for Ben NanoNote Apelete Seketeli
2013-12-14  3:48 ` [PATCH 2/3] usb: musb: add support for JZ4740 usb device controller Apelete Seketeli
2013-12-14  3:48 ` [PATCH 3/3] usb: musb: fix setting JZ4740 gadget periphal mode on reset Apelete Seketeli
2013-12-16 21:20   ` Felipe Balbi [this message]
2013-12-17  1:31     ` Apelete Seketeli
2013-12-17  2:14       ` Felipe Balbi

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