On Mon, Mar 06, 2023 at 11:28:50AM +0100, Nirmoy Das wrote:
> If stolen memory allocation fails for fbdev, the driver will
> fallback to system memory. Calculation of smem_start is wrong
> for such framebuffer objs if the platform comes with no gmadr or
> no aperture. Solve this by adding fb_mmap callback which also gives
> driver more control.
>
> Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_fbdev.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 98ae3a3a986a..ed0f9e2af3ed 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -40,8 +40,10 @@
> #include <drm/drm_crtc.h>
> #include <drm/drm_fb_helper.h>
> #include <drm/drm_fourcc.h>
> +#include <drm/drm_gem_framebuffer_helper.h>
>
> #include "gem/i915_gem_lmem.h"
> +#include "gem/i915_gem_mman.h"
>
> #include "i915_drv.h"
> #include "intel_display_types.h"
> @@ -120,6 +122,23 @@ static int intel_fbdev_pan_display(struct fb_var_screeninfo *var,
> return ret;
> }
>
> +#define to_intel_fbdev(x) container_of(x, struct intel_fbdev, helper)
> +static int intel_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma)
> +{
> + struct intel_fbdev *fbdev = to_intel_fbdev(info->par);
> + struct drm_gem_object *bo = drm_gem_fb_get_obj(&fbdev->fb->base, 0);
> + struct drm_i915_gem_object *obj = to_intel_bo(bo);
> + struct drm_device *dev = fbdev->helper.dev;
You seem to be missing the fb vs. mmio handling here entirely.
> +
> + vma->vm_page_prot =
> + pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
Does that do something sane on eg. !PAT?
> +
> + if (obj->stolen)
> + return vm_iomap_memory(vma, info->fix.smem_start,
> + info->fix.smem_len);
Why doesn't i915_gem_object_mmap() know how to handle stolen?
> +
> + return i915_gem_object_mmap(obj, vma);
> +}
> static const struct fb_ops intelfb_ops = {
> .owner = THIS_MODULE,
> DRM_FB_HELPER_DEFAULT_OPS,
> @@ -131,6 +150,7 @@ static const struct fb_ops intelfb_ops = {
> .fb_imageblit = drm_fb_helper_cfb_imageblit,
> .fb_pan_display = intel_fbdev_pan_display,
> .fb_blank = intel_fbdev_blank,
> + .fb_mmap = intel_fbdev_mmap,
> };
>
> static int intelfb_alloc(struct drm_fb_helper *helper,
> --
> 2.39.0
--
Ville Syrjälä
Intel
