From: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
To: "Du, ChangbinX" <changbinx.du@intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"balbi@ti.com" <balbi@ti.com>,
"sarah.a.sharp@linuxfoundation.org"
<sarah.a.sharp@linuxfoundation.org>, "Wu, Hao" <hao.wu@intel.com>,
"Tang, Jianqiang" <jianqiang.tang@intel.com>,
"Zhuang, Jin Can" <jin.can.zhuang@intel.com>,
"Huang, Xiaochao" <xiaochao.huang@intel.com>
Subject: Re: About TRB_TO_EP_INDEX() macro using
Date: Mon, 5 Aug 2013 16:34:45 +0800 [thread overview]
Message-ID: <20130805083445.GA15885@kroah.com> (raw)
In-Reply-To: <0C18FE92A7765D4EB9EE5D38D86A563A019660C8@SHSMSX103.ccr.corp.intel.com>
On Mon, Aug 05, 2013 at 08:07:25AM +0000, Du, ChangbinX wrote:
> Recently when I check xHCI code, find that some functions try to get EP index
> from a Command Completion Event TRB via TRB_TO_EP_INDEX() macro.
>
> This is totally wrong. The macro definition is:
>
> #define TRB_TO_EP_INDEX(p) ((((p) & (0x1f << 16)) >> 16) - 1)
>
> TRB_TO_EP_INDEX only applies to Transfer Event TRB. But for Command
> Completion Event TRB, there is no Endpoint ID field. So, we cannot directly
> get EP index from these TRBs, but we can find it by the TRB Pointer.
>
> Here list two functions for you to check:
> handle_stopped_endpoint()
> handle_reset_ep_completion()
Care to send a patch showing how you would change this if it is
incorrect?
thanks,
greg k-h
next prev parent reply other threads:[~2013-08-05 8:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-05 8:07 About TRB_TO_EP_INDEX() macro using Du, ChangbinX
2013-08-05 8:34 ` gregkh [this message]
-- strict thread matches above, loose matches on Subject: below --
2013-08-06 8:59 Du, ChangbinX
2013-08-06 9:06 ` 'gregkh@linuxfoundation.org'
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