Date: Thu, 29 Jan 2015 22:57:14 +0300 From: Chagin Dmitry <dchagin@freebsd.org> To: Hans Petter Selasky <hps@selasky.org> Cc: freebsd-usb@freebsd.org Subject: Re: [Bug?] Control Transfers in xHCI Message-ID: <20150129195714.GA3683@dchagin.static.corbina.net> In-Reply-To: <54CA4BE3.2090706@selasky.org> References: <20150129.212550.434561541001871867.okuno.kohji@jp.panasonic.com> <54CA4BE3.2090706@selasky.org>
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On Thu, Jan 29, 2015 at 04:04:03PM +0100, Hans Petter Selasky wrote: > On 01/29/15 13:25, Kohji Okuno wrote: > > Hi HPS, > > > > I found a bug in xHCI device driver. > > > > Acording to extensible-host-controler-interface-usb-xhci.pdf:"3.2.9 > > Control Transfers"... > > > > A Data Stage TD consists of a Data Stage TRB followed by zero or more > > Normal TRBs. If the data is not physically contiguous, Normal TRBs may > > be chained to the Data Stage TRB. > > > > > > But, in the current imprementation, when two or more TRBs are needed, > > the device driver set XHCI_TRB_TYPE_DATA_STAGE to all TRBs. > > This is the violation of the spec. > > > > In my minor xHCI, I encountered strange bubble error in a control > > transfer. After I changed as the following, I succeeded its control > > transfer. > > > > Would you check the following (****)? > > >=20 > Hi Kohji, >=20 > You are correct there is a bug, but your patch is not correct. >=20 > In FreeBSD we allow SETUP and DATA stages to be done as separate jobs.=20 > That means at the entry of creating a new DATA chain, we need to check=20 > if it is there first DATA packet or not. >=20 > Can you test the attached patch and see if it works for you? >=20 patch is lost somewhere, Hans. --=20 Have fun! chd
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