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Subject: Re: [PATCH] usb: dwc2: Fix DMA cache alignment issues
To:     Doug Anderson <dianders@chromium.org>,
        Martin Schiller <ms@dev.tdt.de>,
        Felipe Balbi <felipe.balbi@linux.intel.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        =?UTF-8?B?QW50dGkgU2VwcMOkbMOk?= <a.seppala@gmail.com>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Tomasz Figa <tfiga@chromium.org>
References: <20190218063730.26870-1-ms@dev.tdt.de>
 <CAD=FV=Viag00jL-QRLsnyDoXWT5KFyZ3TnMdTPSJ-dbuNNiFVQ@mail.gmail.com>
From:   Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Message-ID: <7bf6f5dd-6f0f-4470-51c7-d024fc8ef4df@synopsys.com>
Date:   Thu, 30 May 2019 14:29:31 +0400
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On 5/29/2019 10:31 PM, Doug Anderson wrote:
> Hi,
> 
> On Sun, Feb 17, 2019 at 10:37 PM Martin Schiller <ms@dev.tdt.de> wrote:
>>
>> Insert a padding between data and the stored_xfer_buffer pointer to
>> ensure they are not on the same cache line.
>>
>> Otherwise, the stored_xfer_buffer gets corrupted for IN URBs on
>> non-cache-coherent systems. (In my case: Lantiq xRX200 MIPS)
>>
>> Fixes: 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in a more supported way")
>> Fixes: 56406e017a88 ("usb: dwc2: Fix DMA alignment to start at allocated boundary")
>> Signed-off-by: Martin Schiller <ms@dev.tdt.de>
>> ---
>>   drivers/usb/dwc2/hcd.c | 10 +++++++---
>>   1 file changed, 7 insertions(+), 3 deletions(-)
> 
> This patch has been in the back of my mind for a while bug I never got
> around to it.  Today I was debugging memory corruption problems when
> using a webcam on dwc2 on rk3288-veyron-jerry.  This patch appears to
> solve my problems nicely.  Thanks!
> 
> Tested-by: Douglas Anderson <dianders@chromium.org>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
> Cc: <stable@vger.kernel.org>
> 
Acked-by: Minas Harutyunyan <hminas@synopsys.com>