On Tue, Sep 30, 2025 at 09:26:55PM +0000, Jonathan Cavitt wrote: > Add a helper function that computes the product of hdisplay and > vdisplay. > > Signed-off-by: Jonathan Cavitt <jonathan.cav...@intel.com> > Cc: Matthew Auld <matthew.a...@intel.com> > Cc: Himal Prasad Ghimiray <himal.prasad.ghimi...@intel.com> > Cc: Matthew Brost <matthew.br...@intel.com> > --- > drivers/gpu/drm/drm_gem_vram_helper.c | 2 +- > drivers/gpu/drm/drm_mipi_dbi.c | 2 +- > include/drm/drm_modes.h | 5 +++++ > 3 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c > b/drivers/gpu/drm/drm_gem_vram_helper.c > index 90760d0ca071..4ac71c34f4c6 100644 > --- a/drivers/gpu/drm/drm_gem_vram_helper.c > +++ b/drivers/gpu/drm/drm_gem_vram_helper.c > @@ -967,7 +967,7 @@ drm_vram_helper_mode_valid_internal(struct drm_device > *dev, > > max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT; > > - fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
This calculation is quite inaccurate since it doesn't consider any stride alignment requirements. Maybe it works for a few cases, but certainly not usable on most hardware. > + fbsize = drm_mode_display_size(mode) * max_bpp; > fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE); > > if (fbpages > max_fbpages) > diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c > index e33c78fc8fbd..54212bf85160 100644 > --- a/drivers/gpu/drm/drm_mipi_dbi.c > +++ b/drivers/gpu/drm/drm_mipi_dbi.c > @@ -691,7 +691,7 @@ int mipi_dbi_dev_init(struct mipi_dbi_dev *dbidev, > const struct drm_simple_display_pipe_funcs *funcs, > const struct drm_display_mode *mode, unsigned int > rotation) > { > - size_t bufsize = mode->vdisplay * mode->hdisplay * sizeof(u16); > + size_t bufsize = drm_mode_display_size(mode) * sizeof(u16); > > dbidev->drm.mode_config.preferred_depth = 16; > > diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h > index b9bb92e4b029..775c94c55cda 100644 > --- a/include/drm/drm_modes.h > +++ b/include/drm/drm_modes.h > @@ -572,4 +572,9 @@ struct drm_display_mode * > drm_mode_create_from_cmdline_mode(struct drm_device *dev, > struct drm_cmdline_mode *cmd); > > +static inline u32 drm_mode_display_size(const struct drm_display_mode *mode) "display size" isn't really a term that gives me any kind of idea what this does, so the name is rather poor. drm_mode_num_active_pixels() or something might make more sense. But I'm not sure there's much point in this helper since that value is very rarely useful for anything. > +{ > + return mode->hdisplay * mode->vdisplay; > +} > + > #endif /* __DRM_MODES_H__ */ > -- > 2.43.0 -- Ville Syrjälä Intel