From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bin Liu Subject: Re: [OOPS] cppi41_dma_channel_program: Unable to handle kernel NULL pointer dereference Date: Mon, 23 May 2016 08:35:22 -0500 Message-ID: <20160523133522.GA3942@uda0271908> References: <1463750386-6259-1-git-send-email-matwey@sai.msu.ru> <20160520201019.GA3432@uda0271908> <20160520211236.GB3432@uda0271908> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Matwey V. Kornilov" Cc: Bin Liu , Linux OMAP List , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-omap@vger.kernel.org Hi, On Sat, May 21, 2016 at 08:50:32PM +0300, Matwey V. Kornilov wrote: > 2016-05-21 6:13 GMT+03:00 Bin Liu : > > Hi, > > > > On Fri, May 20, 2016 at 4:20 PM, Matwey V. Kornilov wrote: > >> 2016-05-21 0:12 GMT+03:00 Bin Liu : > >>> Hi, > >>> > >>> On Sat, May 21, 2016 at 12:05:06AM +0300, Matwey V. Kornilov wrote: > >>>> By the way, is it ok that function musb_rx_dma_iso_cppi41 uses > >>>> hw_ep->tx_channel? I would suppose that it should use rx_channel > >>>> instead. > >>> > >>> I just got here, and am wondering the same. But the question is why just > >>> your case hit the problem. I will try to look at it more next week. > >>> > >>> I had an impression the linux-usb@ has a discussion before about > >>> rx/tx-channel messing up, will have to look it up. > >>> > >> > >> Thank you. > >> If you need additional info, I can use kgdb with this issue. > > > > After reviewed the code, it must be hw_ep->rx_channel instead. It is likely a > > bug caused by commit 069a3fd (usb: musb: Remove ifdefs for musb_host_rx > > in musb_host.c part1). Please test with the following patch. > > > > I've just tested this patch. Indeed, it helps to avoid kernel panic. Thanks for testing it. > Now, I can interact with my webcam and watch video-stream in xawtv. > It would be great if the patch could become a part of 4.6.x stable tree. Sure. Would you mind to add your Reported-by in the patch? Regards, -Bin. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html