Re: [PATCH v3 6/7] Drivers: hv: vmbus: Get the IRQ number from DT

[Roman Kisel]

On 7/27/2024 1:56 AM, Krzysztof Kozlowski wrote:
> On 27/07/2024 00:59, Roman Kisel wrote:
> > @@ -2338,6 +2372,21 @@ static int vmbus_device_add(struct platform_device *pdev)
> >   		cur_res = &res->sibling;
> >   	}
> >   
> > +	/*
> > +	 * Hyper-V always assumes DMA cache coherency, and the DMA subsystem
> > +	 * might default to 'not coherent' on some architectures.
> > +	 * Avoid high-cost cache coherency maintenance done by the CPU.
> > +	 */
> > +#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
> > +	defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
> > +	defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
> > +
> > +	if (!of_property_read_bool(np, "dma-coherent"))
> > +		pr_warn("Assuming cache coherent DMA transactions, no 'dma-coherent' node supplied\n");
>
> Why do you need this property at all, if it is allways dma-coherent? Are
> you supporting dma-noncoherent somewhere?
No support for non-coherent. Wanted to do a sanity check. Had better 
check for dma-noncoherent and warn about that I believe.

> Best regards,
> Krzysztof

--
Thank you,
Roman