From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Wed, 7 Dec 2016 07:52:00 -0500 Subject: [U-Boot] [PATCH 5/6] mmc: move some SDHCI related options to Kconfig In-Reply-To: References: <1480857794-27145-1-git-send-email-yamada.masahiro@socionext.com> <1480857794-27145-6-git-send-email-yamada.masahiro@socionext.com> <20161205191031.GV4248@bill-the-cat> Message-ID: <20161207125200.GQ4248@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed, Dec 07, 2016 at 06:04:21PM +0900, Masahiro Yamada wrote: > Hi Tom > > 2016-12-06 4:10 GMT+09:00 Tom Rini : > > On Sun, Dec 04, 2016 at 10:23:13PM +0900, Masahiro Yamada wrote: > > > >> While I moved the options, I also renamed them so that they are all > >> prefixed with MMC_SDHCI_. > > [snip] > >> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig > >> index 8e9fa2d..4785d71 100644 > >> --- a/drivers/mmc/Kconfig > >> +++ b/drivers/mmc/Kconfig > >> @@ -132,6 +132,68 @@ config MMC_SDHCI > >> > >> If unsure, say N. > >> > >> +config MMC_SDHCI_SDMA > >> + bool "Support SDHCI SDMA" > >> + depends on MMC_SDHCI > >> + help > >> + This enables support for the SDMA (Single Operation DMA) defined > >> + in the SD Host Controller Standard Specification Version 1.00 . > > > > I think this should be a default y. > > No. > > After my conversion, > > masahiro at pug:~/workspace/u-boot/configs$ git grep CONFIG_MMC_SDHCI=y | wc > 54 54 2306 > masahiro at pug:~/workspace/u-boot/configs$ git grep CONFIG_MMC_SDHCI_SDMA=y | wc > 21 21 995 > > > So, SDMA is disabled for more than half of boards with SDHCI driver. > > > I know one more reason that we should not enable option by default. > > SDMA is so old that it only supports 32 bit physical address. > > U-Boot uses the tail of memory area as work RAM. > > If SDMA is enabled on 64bit boards, MMC does not work > because the controller cannot read EXT-CSD data. > > Given increasing ARMv8 boards, > we want to use ADMA(2), but it is not supported in U-Boot. > > Anyway, I believe SDMA does not deserve default. OK, thanks, agreed! -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: