From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com ([192.55.52.88]:41425 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726010AbeLGNcj (ORCPT ); Fri, 7 Dec 2018 08:32:39 -0500 Date: Fri, 7 Dec 2018 15:32:35 +0200 From: Andy Shevchenko To: Vinod Koul Cc: Viresh Kumar , dmaengine@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2 1/7] dmaengine: dw: Add missed multi-block support for iDMA 32-bit Message-ID: <20181207133235.GG10650@smile.fi.intel.com> References: <20181205162818.45112-1-andriy.shevchenko@linux.intel.com> <20181205162818.45112-2-andriy.shevchenko@linux.intel.com> <20181205181202.GV2847@vkoul-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181205181202.GV2847@vkoul-mobl> Sender: stable-owner@vger.kernel.org List-ID: On Wed, Dec 05, 2018 at 11:42:02PM +0530, Vinod Koul wrote: > On 05-12-18, 18:28, Andy Shevchenko wrote: > > Intel integrated DMA 32-bit support multi-block transfers. > > Add missed setting to the platform data. > > > > Fixes: f7c799e950f9 ("dmaengine: dw: we do support Merrifield SoC in PCI mode") > > Signed-off-by: Andy Shevchenko > > Cc: stable@vger.kernel.org > > How is this a stable material? It would improve performance by using multi > blocks but given the fact that this is used for slow peripherals, do you > really see a user impact? Last my testing was done with SPI VGA panel connected and I ran few FB based tests with more or less good FPS numbers. So, I can't tell about notable user impact. Feel free not to add for stable. Btw, I have tested via DMA test, where it's indeed at least visible, but still memory-to-memory is not what that DMA is used for. > > --- > > drivers/dma/dw/pci.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/dma/dw/pci.c b/drivers/dma/dw/pci.c > > index 7778ed705a1a..313ba10c6224 100644 > > --- a/drivers/dma/dw/pci.c > > +++ b/drivers/dma/dw/pci.c > > @@ -25,6 +25,7 @@ static struct dw_dma_platform_data mrfld_pdata = { > > .block_size = 131071, > > .nr_masters = 1, > > .data_width = {4}, > > + .multi_block = {1, 1, 1, 1, 1, 1, 1, 1}, > > }; > > > > static int dw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *pid) > > -- > > 2.19.2 > > -- > ~Vinod -- With Best Regards, Andy Shevchenko