linux-kernel - Re: [PATCH 5/6] driver core: lift dma_default

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Message-ID: <20210209130636.GA11915@alpha.franken.de>
Date:   Tue, 9 Feb 2021 14:06:36 +0100
From:   Thomas Bogendoerfer <tsbogend@...ha.franken.de>
To:     Christoph Hellwig <hch@....de>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-mips@...r.kernel.org, linux-kernel@...r.kernel.org,
        iommu@...ts.linux-foundation.org
Subject: Re: [PATCH 5/6] driver core: lift dma_default_coherent into common
 code

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@....de>
> ---
> [..]
> @@ -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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