[RFC 0/4] Support SDMA mode on RPI4 target - 32bit

[Peter Robinson]

> RPI4's SDHCI controller is supported SDMA mode. (Checked on kernel side)
> But It doesn't use on u-boot side. Then it's too slow about read/write performance.
> This patchset is supported SDMA mode on RPI4 target(32bit).
> - I didn't test on RPI4 64bit.

What about on other models of the rpi given they all use the same
sdhci controller?

> Read/write time about 8MB file
> Before
> - Read : 1.472 seconds
> - Write : 4.690 seconds
> After
> - Read : 0.359 seconds
> - Write : 0.574 seconds
>
> Jaehoon Chung (4):
>   mmc: bcm2835_sdhci: use phys2bus macro when dma address is accessed
>   mmc: sdhci: add quriks relevant to broken SDMA
>   mmc: bcm2835_sdhci: set SDHCI_QUIRK_BROKEN_SDMA flag
>   configs: rpi_4_32b_defconfig: enable SDHCI_SDMA config
>
>  configs/rpi_4_32b_defconfig |  1 +
>  drivers/mmc/bcm2835_sdhci.c | 10 ++++++++--
>  drivers/mmc/sdhci.c         | 10 ++++++++--
>  include/sdhci.h             |  1 +
>  4 files changed, 18 insertions(+), 4 deletions(-)
>
> --
> 2.25.0
>