Hi Philipp, > -----Original Message----- > From: Philipp Tomsich [mailto:philipp.toms...@theobroma-systems.com] > Sent: Friday, November 30, 2018 2:40 PM > To: u-boot@lists.denx.de > Cc: Tom Rini <tr...@konsulko.com>; Philipp Tomsich > <philipp.toms...@theobroma-systems.com>; Mario Six <mario....@gdsys.cc>; > Michal Simek <michal.si...@xilinx.com>; Simon Glass <s...@chromium.org>; > Masahiro Yamada > <yamada.masah...@socionext.com>; Alexey Brodkin > <alexey.brod...@synopsys.com>; Alex Kiernan <alex.kier...@gmail.com>; Eric > Nelson <e...@nelint.com>; Marek Vasut <marek.va...@gmail.com>; Jörg Krause > <joerg.krause@embedded.rocks>; Adam Ford > <aford...@gmail.com>; Stephen Warren <swar...@nvidia.com>; Angelo Dureghello > <ang...@sysam.it>; Tuomas Tynkkynen > <tuomas.tynkky...@iki.fi>; Eugeniu Rosca <roscaeuge...@gmail.com> > Subject: [PATCH 1/6] Kconfig: Migrate BOUNCE_BUFFER > > The bounce buffer is used by a few drivers (most of the MMC drivers) > to overcome limitations in their respective DMA implementation. > > This moves the configuration to Kconfig and makes it user-selectable > (even though it will be a required feature to make those drivers > work): the expected usage is for drivers depending on this to 'select' > it unconditionally from their respective Kconfig. > > Signed-off-by: Philipp Tomsich <philipp.toms...@theobroma-systems.com> > > --- > > common/Kconfig | 8 ++++++++ > scripts/config_whitelist.txt | 1 - > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/common/Kconfig b/common/Kconfig > index 57bd16d..f45e066 100644 > --- a/common/Kconfig > +++ b/common/Kconfig > @@ -645,6 +645,14 @@ config DISPLAY_BOARDINFO_LATE > the relocation phase. The board function checkboard() is called to do > this. > > +config BOUNCE_BUFFER > + bool "Include bounce buffer API" > + help > + Some peripherals support DMA from a subset of physically > + addressable memory only. To support such peripherals, the > + bounce buffer API uses a temporary buffer: it copies data > + to/from DMA regions while managing cache operations.
IIRC I decided to use bounce buffer just to make sure data we pass to the DMA is properly aligned. Not sure though if that's a valid use-case for it but if it is IMHO it worth mentioning here in this help message. -Alexey _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
