Re: [PATCH] drm/fbdev-dma: Add shadow buffering for deferred I/O

Simona Vetter writes: > On Wed, Dec 11, 2024 at 10:06:28AM +0100, Thomas Zimmermann wrote: >> DMA areas are not necessarily backed by struct page, so we cannot >> rely on it for deferred I/O. Allocate a shadow buffer for drivers >> that require deferred I/O and use it as framebuffer memory. >> >

Re: [PATCH] drm/fbdev-dma: Add shadow buffering for deferred I/O

On Wed, Dec 11, 2024 at 10:06:28AM +0100, Thomas Zimmermann wrote: > DMA areas are not necessarily backed by struct page, so we cannot > rely on it for deferred I/O. Allocate a shadow buffer for drivers > that require deferred I/O and use it as framebuffer memory. > > Fixes driver errors about bei

[PATCH] drm/fbdev-dma: Add shadow buffering for deferred I/O

DMA areas are not necessarily backed by struct page, so we cannot rely on it for deferred I/O. Allocate a shadow buffer for drivers that require deferred I/O and use it as framebuffer memory. Fixes driver errors about being "Unable to handle kernel NULL pointer dereference at virtual address" or "