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 ; Philipp Tomsich
> ; Mario Six ;
> Michal Simek ; Simon Glass ;
> Masahiro Yamada
> ; Alexey Brodkin
> ; Alex Kiernan ; Eric
> Nelson ; Marek Vasut ; Jörg Krause
> ; Adam Ford
> ; Stephen Warren ; Angelo Dureghello
> ; Tuomas Tynkkynen
> ; Eugeniu Rosca
> 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
>
> ---
>
> 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
