From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinod Subject: Re: [PATCH v4 11/18] dmaengine: dma-jz4780: Add missing residue DTC mask Date: Mon, 27 Aug 2018 10:30:57 +0530 Message-ID: <20180827050057.GR2388@vkoul-mobl> References: <20180807114218.20091-1-paul@crapouillou.net> <20180807114218.20091-12-paul@crapouillou.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180807114218.20091-12-paul@crapouillou.net> Sender: linux-kernel-owner@vger.kernel.org To: Paul Cercueil Cc: Rob Herring , Mark Rutland , Ralf Baechle , Paul Burton , James Hogan , Zubair Lutfullah Kakakhel , dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, Daniel Silsby List-Id: devicetree@vger.kernel.org On 07-08-18, 13:42, Paul Cercueil wrote: > From: Daniel Silsby > > The 'dtc' word in jz DMA descriptors contains two fields: The > lowest 24 bits are the transfer count, and upper 8 bits are the DOA > offset to next descriptor. The upper 8 bits are now correctly masked > off when computing residue in jz4780_dma_desc_residue(). Note that > reads of the DTCn hardware reg are automatically masked this way. > > Signed-off-by: Daniel Silsby > Signed-off-by: Paul Cercueil > Tested-by: Mathieu Malaterre > --- > drivers/dma/dma-jz4780.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > v2: No change > > v3: No change > > v4: Add my Signed-off-by > > diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c > index 3a4d0a4b550d..a4292ac4c686 100644 > --- a/drivers/dma/dma-jz4780.c > +++ b/drivers/dma/dma-jz4780.c > @@ -616,7 +616,8 @@ static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan, > residue = 0; > > for (i = next_sg; i < desc->count; i++) > - residue += desc->desc[i].dtc << jzchan->transfer_shift; > + residue += (desc->desc[i].dtc & 0xffffff) << GENMASK(23, 0) please. -- ~Vinod