Re: [PATCH] Revert "dma-contiguous: do not allocate a single page from CMA area"

[Krzysztof Kozlowski]

On Tue, 26 Feb 2019 at 21:25, Nicolin Chen <nicoleotsuka@xxxxxxxxx> wrote:
>
> This reverts commit d222e42e88168fd67e6d131984b86477af1fc256.
>
> The original change breaks omap dss:
>     omapdss_dispc 58001000.dispc:
>         dispc_errata_i734_wa_init: dma_alloc_writecombine failed
>
> Let's revert it first and then find a safer solution instead.
>
> Reported-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Signed-off-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx>
> ---
> Tony,
>
> Would you please test and verify? Thanks!
>
>  kernel/dma/contiguous.c | 22 +++-------------------
>  1 file changed, 3 insertions(+), 19 deletions(-)

This fixes broken (since yesterday) linux-next on Exynos boards
(ARMv7), errors like:
dma-pl330: probe of 121a0000.pdma failed with error -12
exynos-ehci 12110000.usb: can't setup: -12
exynos-ehci 12110000.usb: USB bus 1 deregistered
exynos-ehci 12110000.usb: Failed to add USB HCD

Tested-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

Best regards,
Krzysztof