Messages in this thread | | | Date | Mon, 21 Jan 2019 07:07:34 -0800 | From | Christoph Hellwig <> | Subject | Re: [RFC PATCH] drm: disable WC optimization for cache coherent devices on non-x86 |
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> +#include <linux/dma-noncoherent.h>
This header is not for usage in device drivers, but purely for dma-mapping implementations!
> +static inline bool drm_device_can_wc_memory(struct drm_device *ddev) > { > + if (IS_ENABLED(CONFIG_PPC)) > + return IS_ENABLED(CONFIG_NOT_COHERENT_CACHE); > + else if (IS_ENABLED(CONFIG_MIPS)) > + return !IS_ENABLED(CONFIG_CPU_LOONGSON3); > + else if (IS_ENABLED(CONFIG_X86)) > + return true; > + > + return !dev_is_dma_coherent(ddev->dev);
And even if something like this was valid to do, it would have to be a core function with an arch hook, and not hidden in a random driver.
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