Re: [PATCH 5/6] driver core: lift dma_default_coherent into common code

From: Thomas Bogendoerfer
Date: Tue Feb 09 2021 - 08:14:09 EST


On Mon, Feb 08, 2021 at 03:50:23PM +0100, Christoph Hellwig wrote:
> Lift the dma_default_coherent variable from the mips architecture code
> to the driver core. This allows an architecture to sdefault all device
> to be DMA coherent at run time, even if the kernel is build with support
> for DMA noncoherent device. By allowing device_initialize to ѕet the
> ->dma_coherent field to this default the amount of arch hooks required
> for this behavior can be greatly reduced.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> [..]
> @@ -143,7 +143,7 @@ static void __init plat_setup_iocoherency(void)
> pr_crit("IOCU OPERATION DISABLED BY SWITCH - DEFAULTING TO SW IO COHERENCY\n");
> }
>
> - if (supported)
> + if (supported) {
> if (dma_force_noncoherent) {
> pr_info("Hardware DMA cache coherency disabled\n");
> return;

this hunk needs to be in patch 1, otherwise it's not compilable

Thomas.

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