From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Shilimkar, Santosh" Subject: Re: [PATCH 1/1] mmc: host: enable OMAP DMA engine support for omap hosts by default Date: Wed, 18 Jul 2012 14:41:08 +0530 Message-ID: References: <1342485005-5178-1-git-send-email-javier@dowhile0.org> <20120718065951.GH6522@atomide.com> <20120718071039.GI6522@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: Sender: linux-omap-owner@vger.kernel.org To: Javier Martinez Canillas Cc: "S, Venkatraman" , Tony Lindgren , Javier Martinez Canillas , Kevin Hilman , Russell King , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Chris Ball , linux-mmc@vger.kernel.org List-Id: linux-mmc@vger.kernel.org On Wed, Jul 18, 2012 at 2:19 PM, Javier Martinez Canillas wrote: > On Wed, Jul 18, 2012 at 10:36 AM, Shilimkar, Santosh > wrote: >> On Wed, Jul 18, 2012 at 1:14 PM, S, Venkatraman wrote: >>> On Wed, Jul 18, 2012 at 12:40 PM, Tony Lindgren wrote: >>>> * Shilimkar, Santosh [120718 00:09]: >>>>> On Wed, Jul 18, 2012 at 12:29 PM, Tony Lindgren wrote: >>>>> > * Javier Martinez Canillas [120716 23:56]: >>>>> >> On Tue, Jul 17, 2012 at 8:45 AM, Shilimkar, Santosh >>>>> >> wrote: >>>>> >> > Hi, >>>>> >> > >>>>> >> > On Tue, Jul 17, 2012 at 6:00 AM, Javier Martinez Canillas >>>>> >> > wrote: >>>>> >> >> The OMAP MMC and OMAP High Speed MMC hosts now use entirely the DMA >>>>> >> >> engine API instead of the previous private DMA API implementation. >>>>> >> >> >>>>> >> >> So, if the kernel is built with support for any of these hosts but it >>>>> >> >> doesn't support DMA devices nor OMAP DMA support, it fails when trying >>>>> >> >> to obtain a DMA channel which leads to the following error on an OMAP3 >>>>> >> >> IGEPv2 Rev.C board (and probably on most OMAP boards with MMC support): >>>>> >> >> >>>>> >> >> [ 2.199981] omap_hsmmc omap_hsmmc.1: unable to obtain RX DMA engine channel 48 >>>>> >> >> [ 2.215087] omap_hsmmc omap_hsmmc.0: unable to obtain RX DMA engine channel 62 >>>>> >> >> >>>>> >> >> selecting automatically CONFIG_DMADEVICES and CONFIG_DMA_OMAP solves it. >>>>> >> >> >>>>> >> >> Signed-off-by: Javier Martinez Canillas >>>>> >> >> --- >>>>> >> > Considering, we are updating drivers to select the DMA engine, can you >>>>> >> > also include >>>>> >> > "drivers/spi/spi-omap2-mcspi.c" which is also updated for DMA engine. >>>>> >> > >>>>> >> > Regards >>>>> >> > Santosh >>>>> >> >>>>> >> Hi Santosh, >>>>> >> >>>>> >> Ok, I'll send a v2 now which includes spi-omap2-mcspi then. >>>>> > >>>>> > I don't think we should do this, the drivers should work with and without >>>>> > dma. This just needs to be added to the omap2plus_defconfig. >>>>> > >>>>> Well this was not decided based on any DMA CONFIG option before for >>>>> the subject drivers. It is already by default enabled if the DMA is supported >>>>> by the driver IP. There is a possibility to disable it from driver platform/dt >>>>> data so that still remains. >>>> >>>> I think it should rather be that if the driver is broken and does not work >>>> without DMA, it should have depends on CONFIG_DMA_OMAP. >>>> >>> I can confirm that omap MMC can't work without DMA; polled mode is not >>> supported / implemented. >> >> Same case for SPI driver as well. It uses DMA for everything except the cases >> where DMA doesn't make sense like 1 byte/2 byte etc. And its not configurable, >> >> At least considering this, it is better we do this per driver than enabling >> it at SOC config. >> >> Regards >> Santosh >> -- > > Hi Santosh, > > And what about enabling it at the SoC config level but making the > drivers dependant on CONFIG_DMADEVICES and CONFIG_DMA_OMAP? If you > agree I can send something like this in two different patches (one for > the omap2plus_defconfig and another to make the drivers dependant on > the config option): > > diff --git a/arch/arm/configs/omap2plus_defconfig > b/arch/arm/configs/omap2plus_defconfig > index b152de7..e58edc3 100644 > --- a/arch/arm/configs/omap2plus_defconfig > +++ b/arch/arm/configs/omap2plus_defconfig > @@ -193,6 +193,8 @@ CONFIG_MMC_OMAP_HS=y > CONFIG_RTC_CLASS=y > CONFIG_RTC_DRV_TWL92330=y > CONFIG_RTC_DRV_TWL4030=y > +CONFIG_DMADEVICES=y > +CONFIG_DMA_OMAP=y > CONFIG_EXT2_FS=y > CONFIG_EXT3_FS=y > # CONFIG_EXT3_FS_XATTR is not set > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > index aa131b3..314c7bd 100644 > --- a/drivers/mmc/host/Kconfig > +++ b/drivers/mmc/host/Kconfig > @@ -231,7 +231,7 @@ config MMC_SDHCI_S3C_DMA > > config MMC_OMAP > tristate "TI OMAP Multimedia Card Interface support" > - depends on ARCH_OMAP > + depends on ARCH_OMAP && DMADEVICES && DMA_OMAP May be. But since for sure a driver knows that it needs DMA support to be enabled, I will just select it rather than depends on. Regards santosh From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Shilimkar, Santosh) Date: Wed, 18 Jul 2012 14:41:08 +0530 Subject: [PATCH 1/1] mmc: host: enable OMAP DMA engine support for omap hosts by default In-Reply-To: References: <1342485005-5178-1-git-send-email-javier@dowhile0.org> <20120718065951.GH6522@atomide.com> <20120718071039.GI6522@atomide.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jul 18, 2012 at 2:19 PM, Javier Martinez Canillas wrote: > On Wed, Jul 18, 2012 at 10:36 AM, Shilimkar, Santosh > wrote: >> On Wed, Jul 18, 2012 at 1:14 PM, S, Venkatraman wrote: >>> On Wed, Jul 18, 2012 at 12:40 PM, Tony Lindgren wrote: >>>> * Shilimkar, Santosh [120718 00:09]: >>>>> On Wed, Jul 18, 2012 at 12:29 PM, Tony Lindgren wrote: >>>>> > * Javier Martinez Canillas [120716 23:56]: >>>>> >> On Tue, Jul 17, 2012 at 8:45 AM, Shilimkar, Santosh >>>>> >> wrote: >>>>> >> > Hi, >>>>> >> > >>>>> >> > On Tue, Jul 17, 2012 at 6:00 AM, Javier Martinez Canillas >>>>> >> > wrote: >>>>> >> >> The OMAP MMC and OMAP High Speed MMC hosts now use entirely the DMA >>>>> >> >> engine API instead of the previous private DMA API implementation. >>>>> >> >> >>>>> >> >> So, if the kernel is built with support for any of these hosts but it >>>>> >> >> doesn't support DMA devices nor OMAP DMA support, it fails when trying >>>>> >> >> to obtain a DMA channel which leads to the following error on an OMAP3 >>>>> >> >> IGEPv2 Rev.C board (and probably on most OMAP boards with MMC support): >>>>> >> >> >>>>> >> >> [ 2.199981] omap_hsmmc omap_hsmmc.1: unable to obtain RX DMA engine channel 48 >>>>> >> >> [ 2.215087] omap_hsmmc omap_hsmmc.0: unable to obtain RX DMA engine channel 62 >>>>> >> >> >>>>> >> >> selecting automatically CONFIG_DMADEVICES and CONFIG_DMA_OMAP solves it. >>>>> >> >> >>>>> >> >> Signed-off-by: Javier Martinez Canillas >>>>> >> >> --- >>>>> >> > Considering, we are updating drivers to select the DMA engine, can you >>>>> >> > also include >>>>> >> > "drivers/spi/spi-omap2-mcspi.c" which is also updated for DMA engine. >>>>> >> > >>>>> >> > Regards >>>>> >> > Santosh >>>>> >> >>>>> >> Hi Santosh, >>>>> >> >>>>> >> Ok, I'll send a v2 now which includes spi-omap2-mcspi then. >>>>> > >>>>> > I don't think we should do this, the drivers should work with and without >>>>> > dma. This just needs to be added to the omap2plus_defconfig. >>>>> > >>>>> Well this was not decided based on any DMA CONFIG option before for >>>>> the subject drivers. It is already by default enabled if the DMA is supported >>>>> by the driver IP. There is a possibility to disable it from driver platform/dt >>>>> data so that still remains. >>>> >>>> I think it should rather be that if the driver is broken and does not work >>>> without DMA, it should have depends on CONFIG_DMA_OMAP. >>>> >>> I can confirm that omap MMC can't work without DMA; polled mode is not >>> supported / implemented. >> >> Same case for SPI driver as well. It uses DMA for everything except the cases >> where DMA doesn't make sense like 1 byte/2 byte etc. And its not configurable, >> >> At least considering this, it is better we do this per driver than enabling >> it at SOC config. >> >> Regards >> Santosh >> -- > > Hi Santosh, > > And what about enabling it at the SoC config level but making the > drivers dependant on CONFIG_DMADEVICES and CONFIG_DMA_OMAP? If you > agree I can send something like this in two different patches (one for > the omap2plus_defconfig and another to make the drivers dependant on > the config option): > > diff --git a/arch/arm/configs/omap2plus_defconfig > b/arch/arm/configs/omap2plus_defconfig > index b152de7..e58edc3 100644 > --- a/arch/arm/configs/omap2plus_defconfig > +++ b/arch/arm/configs/omap2plus_defconfig > @@ -193,6 +193,8 @@ CONFIG_MMC_OMAP_HS=y > CONFIG_RTC_CLASS=y > CONFIG_RTC_DRV_TWL92330=y > CONFIG_RTC_DRV_TWL4030=y > +CONFIG_DMADEVICES=y > +CONFIG_DMA_OMAP=y > CONFIG_EXT2_FS=y > CONFIG_EXT3_FS=y > # CONFIG_EXT3_FS_XATTR is not set > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > index aa131b3..314c7bd 100644 > --- a/drivers/mmc/host/Kconfig > +++ b/drivers/mmc/host/Kconfig > @@ -231,7 +231,7 @@ config MMC_SDHCI_S3C_DMA > > config MMC_OMAP > tristate "TI OMAP Multimedia Card Interface support" > - depends on ARCH_OMAP > + depends on ARCH_OMAP && DMADEVICES && DMA_OMAP May be. But since for sure a driver knows that it needs DMA support to be enabled, I will just select it rather than depends on. Regards santosh