From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Subject: Re: [PATCH v2] mmc: sdhi: use maximum width for the sdbuf register Date: Thu, 10 Aug 2017 09:53:10 +0200 Message-ID: <20170810075309.GC16647@verge.net.au> References: <20170809182926.669-1-wsa+renesas@sang-engineering.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170809182926.669-1-wsa+renesas@sang-engineering.com> Sender: linux-renesas-soc-owner@vger.kernel.org To: Wolfram Sang Cc: linux-mmc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Biju Das List-Id: linux-mmc@vger.kernel.org On Wed, Aug 09, 2017 at 08:29:26PM +0200, Wolfram Sang wrote: > Make use of the 64 bit sdbuf width on Renesas R-Car Gen3. If the > registers are 8 byte apart, the width is also 64 bit. For all others, > the width is 32 bit, even if the registers are only 16 bit apart. > > Signed-off-by: Wolfram Sang Reviewed-by: Simon Horman > --- > > Change since v1: > * width calculation is now fully backwards compatible. If it is not 8 byte > apart (which is only on Gen3), we will always default to 32 as before. > Thanks to Biju Das and Simon Horman for the error reports! > > Tested on a M3-W Salvator-X and H2 Lager (with both SDHI instances). On > the Lager, I could reproduce the problem with the old patch. It is gone now! Do you think there is any value in widening the test-coverage of this change, f.e. to older SoCs? > drivers/mmc/host/renesas_sdhi_core.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c > index dd215723fa4312..a252145097d6a5 100644 > --- a/drivers/mmc/host/renesas_sdhi_core.c > +++ b/drivers/mmc/host/renesas_sdhi_core.c > @@ -459,10 +459,11 @@ static int renesas_sdhi_multi_io_quirk(struct mmc_card *card, > > static void renesas_sdhi_enable_dma(struct tmio_mmc_host *host, bool enable) > { > - sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? DMA_ENABLE_DMASDRW : 0); > + /* Iff regs are 8 byte apart, sdbuf is 64 bit. Otherwise always 32. */ > + int width = (host->bus_shift == 2) ? 64 : 32; > > - /* enable 32bit access if DMA mode if possibile */ > - renesas_sdhi_sdbuf_width(host, enable ? 32 : 16); > + sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? DMA_ENABLE_DMASDRW : 0); > + renesas_sdhi_sdbuf_width(host, enable ? width : 16); > } > > int renesas_sdhi_probe(struct platform_device *pdev, > -- > 2.11.0 >