From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932953AbcBILGz (ORCPT ); Tue, 9 Feb 2016 06:06:55 -0500 Received: from mail-lb0-f169.google.com ([209.85.217.169]:33580 "EHLO mail-lb0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932403AbcBILGx (ORCPT ); Tue, 9 Feb 2016 06:06:53 -0500 Subject: Re: [PATCH v2 1/2] usb: musb: Fix DMA for host mode To: Joshua Henderson , linux-kernel@vger.kernel.org References: <1454969730-18480-1-git-send-email-joshua.henderson@microchip.com> Cc: Cristian Birsan , Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org From: Sergei Shtylyov Message-ID: <56B9C84A.6090104@cogentembedded.com> Date: Tue, 9 Feb 2016 14:06:50 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <1454969730-18480-1-git-send-email-joshua.henderson@microchip.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/9/2016 1:15 AM, Joshua Henderson wrote: > From: Cristian Birsan > > Commit ac33cdb16681 ("usb: musb: Remove ifdefs for musb_host_rx in > musb_host.c part5") introduces a problem setting DMA host mode. > > This commit fixes the done condition that advances the musb schedule. > Without this patch the the msub_advance_schedule() is called immediately > after receiving an endpoint rx interrupt without waiting for the dma > transfer to complete. As a consequence when the dma complete interrupt > arrives the in_qh member of hw_ep is already null an the musb_host_rx() > exits on !urb error case. > > Signed-off-by: Cristian Birsan > Signed-off-by: Joshua Henderson > --- > Changes since v1: > - Don't add unecessary new variable. Just correct done. > --- > drivers/usb/musb/musb_host.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c > index 795a45b..6bef86f 100644 > --- a/drivers/usb/musb/musb_host.c > +++ b/drivers/usb/musb/musb_host.c > @@ -2006,9 +2006,15 @@ void musb_host_rx(struct musb *musb, u8 epnum) > done = musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh, > urb, xfer_len, > iso_err); > - if (done) > + if (done) { > + /* Don't call msub_advance_schedule() > + * immediately after receiving an endpoint RX > + * interrupt without waiting for the DMA > + * transfer to complete. > + */ > + done = false; > goto finish; By not needing the 'ret' variable I meant that you should just call musb_rx_dma_in_inventra_cppi41() directly from *if*. > - else > + } else > dev_err(musb->controller, "error: rx_dma failed\n"); Need to enclose all branches in {} if at least one is enclosed. MBR, Sergei