From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Date: Tue, 29 Oct 2013 12:12:49 +0000 Subject: Re: [PATCH 08/19] mmc: sdhi: Enable the driver on all ARM platforms Message-Id: <526FA641.9090300@cogentembedded.com> List-Id: References: <1383004027-25036-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <1383004027-25036-9-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <4906973.ikaOXXr4gP@avalon> In-Reply-To: <4906973.ikaOXXr4gP@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hello. On 29-10-2013 13:52, Laurent Pinchart wrote: >>> Renesas ARM platforms are transitioning from single-platform to >>> multi-platform kernels using the new ARCH_SHMOBILE_MULTI. Make the >>> driver available on all ARM platforms to enable it on both ARCH_SHMOBILE >>> and ARCH_SHMOBILE_MULTI and increase build testing coverage. >>> Cc: Chris Ball >>> Cc: Guennadi Liakhovetski >>> Cc: Ian Molton >>> Cc: linux-mmc@vger.kernel.org >>> Signed-off-by: Laurent Pinchart >>> [...] >>> diff --git a/drivers/mmc/host/tmio_mmc_dma.c >>> b/drivers/mmc/host/tmio_mmc_dma.c index 65edb4a..535bc35 100644 >>> --- a/drivers/mmc/host/tmio_mmc_dma.c >>> +++ b/drivers/mmc/host/tmio_mmc_dma.c >>> @@ -28,7 +28,7 @@ void tmio_mmc_enable_dma(struct tmio_mmc_host *host, >>> bool enable)> >>> if (!host->chan_tx || !host->chan_rx) >>> >>> return; >>> >>> -#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE) >>> +#if defined(CONFIG_SUPERH) || defined(CONFIG_ARM) >> I'm not sure about this one. In principle DMA so far is only used on SDHI >> with TMIO. But this #if was for a theoretical case, when a TMIO MMC IP >> inside an MFD is also used with DMA. Bus since I had no indormation about >> whether the CTL_DMA_ENABLE register was SDHI specific or not, I put it >> under an #if for the time being. In any case, I don't think making it >> #ifdef CONFIG_ARM makes much sense. We can either remove the #if >> completely, or keep it to limit the scope of this write to sh-mobile >> arches. > SUPERH || ARCH_SHMOBILE covers all the platforms this driver currently builds > on. Now that we're adding ARCH_SHMOBILE_MULTI the #if needs to cover that case > as well. I'm fine with limiting the CTL_DMA_ENABLE write to SUPERH only (which > would modify the driver's behaviour) I'm afraid that would break the driver's ability to work in DMA mode on SH-Mobile SoCs. > or enabling it unconditionally, but I > don't think adding a defined(CONFIG_ARCH_SHMOBILE_MULTI) to the above #if > makes sense, unless there's a plan to add support for DMA for non-SH > (including both SUPERH and ARCH_SHMOBILE) platforms. Not only the plan -- I have already posted the patches to do it for R8A777x, and Simon has queued them for 3.13. >>> /* Switch DMA mode on or off - SuperH specific? */ >>> sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0); >>> >>> #endif WBR, Sergei